I'll address your points one by one:
1. First of all, the "giant hordes of enemies" I'm referring to is in Pillars of Eternity obviously, don't play coy. The game is chockful of areas where there are just absolute armadas of enemies just out in the open simply because you have a large party. For example, a simple battle to defend your keep at Caed Nua could contain something as ridiculous as 6 Ogres at once, which is no easy thing to take down, especially if you don't have a Fighter with Knock-Down. They made it this way so the game would feel challenging because there's tons and tons of enemies to deal with, they've said as much themselves. However, by scaling the party back they are also going to improve the AI for enemies. They haven't gone into too much detail about this, but I would imagine it means the enemy will use more tactical manuevers. For example, in Pillars, most enemies would simply bumrush you and try to overrun your position, but that was pretty much the main strategy. The only time the enemy was really smart was boss fights and bounties.
Let's take Sly Cyrdel for example. He has improved AI over most enemies because he actually "thinks", so to speak. Rather than simply charging into your tanks like everyone else while your long-ranged fighters chill in the back and take it easy, just launching spells at everything that comes near your front-line, he would actually go AROUND your front-line and aim straight for the squishies in the back, such as your wizard or priest. Tactics like these were very rare in the game because for the most part they chose to throw big big piles of enemies all at once at the player for difficulty rather than making AI better for all enemies that weren't "boss level". Tyranny will basically have it so a lot more enemies act as something like Sly Crydel does, with actual tactics and thinking.
Honestly there are no smart enemies in POE, and neither in any real time rpg that i remember, most of the difficulty and interesting parts of POE come out because of the varied enemies and encounters and the somewhat complex mechanics, which let's you play with different variables. Fighting a bunch of spirits in a lighthouse is very different from fighting a bunch of human enemies, which is very different from fighting a bunch of ogres, which is different from fighting a bunch of Pŵgra. The bounty battle you described is precisely how many battles with spirits (or Pŵgra) end up for me and they are actually much more interesting, because not only do they often try to go for the casters, they are also very unpredictable with their teleportation and mind spells, sometimes lulling you into a false sense of security and then instantly changing the flow of the battle with a few spells. I found the bounties pretty boring overall.
What exactly have they in store for Tyranny that will make the game much more tactical and interesting? I would understand if they would go with something like DOS turn based combat system with destructible objects and elements that interact with each other, but from what little i have seen, there is no indication that they magically enhanced the A.I in way that would make the battles much more tactical, or even as tactical. Is there some footage of this at play?
For the "hordes of enemies" argument, well have you played IW2, or BG2? POE pales in comparison and i personally don't see a problem there at all, it never even entered my mind.
2. [Honest 3] I disagree with this assessment. The problem here is that there really doesn't seem to be a point for having 2 health bars. Basically once your Endurance drops to 0 your character is out of the race anyway, and even if you manage to keep healing and tanking eventually your health is going to catch up with you and you'll die regardless. I've lost a LOT of battles in my POE solo run because even though I can keep my Endurance up just fine, my health will keep dropping anyway from every single little thing that grazes me. The main issue is that, as I said, every time you get hit you lose a chunk of your main health even if your endurance doesn't suffer a lick. This will eventually lead to you being killed regardless, and the ONLY spell in the game that restores regular health as opposed to endurance is complete shit and barely fills up 1/6th of the bar. The only point it seems to me for the 2nd health bar is the camp fire mechanic. If you don't rest eventually and your main health gets too low, you'll end up dying no matter what your Endurance is. That seems like it was the point but it's also asinine in the way it was executed. It just doesn't work as strategic, it's more annoying than anything. Why am I able to heal my Endurance up completely during battle with my Priest's 20 different Endurance healing spells, but I can't do anything about my main health going down regardless? If they had just added some regular health spells besides Field Triage (garbage) then this wouldn't be too much of an issue, but they didn't.
But now you are talking about your solo run, which is a different endeavor from a party based run, where you have a tank that regenerates endurance differently and can wake up from being knocked down with "second wind" ability, while squishy characters have to be "revived". The part i do agree with, is the camping mechanics, because you can always backpedal to town for camping supplies. If they made areas that had a couple of battles without backpedaling this would have ended up as a very strategic (in practice) component when choosing your companions for some dungeon. And i don't get how healing endurance is more silly than healing chopped off limbs and reviving the dead, at least here death is death.
Although i feel this is an interesting mechanic in POE, i don't feel as strongly about it's absence, as the smaller party.
3. Well as I said, you'll most likely have the option to leave that on. As for me, I can't stand friendly fire on spells, because it basically means AOE nondamaging spells that cause things such as fear, hobble, paralyzation, etc with friendly fire are never going to get used, because damage is one thing but crippling my own fighters the exact same amount as my enemies makes them all worthless. There's not really a way to strategize this either as many parts of the game take place in narrow hallways, and not to mention the pathfinding in the game isn't outstanding. I've had many a time where my party members will suddenly be engaged in battle out of nowhere and I won't be able to move my fighters to a strategic position because they get stuck behind another party member/a summon/an enemy/etc. If the game had more open areas and didn't have so many enemies at once all the damn time then sure, I wouldn't mind friendly-fire on at all. But the issue here is, it doesn't. Many areas are very tight or at the very least difficult to move around in with wide berth so you can actually get some big spells off without hitting your own party. Do you see what I'm saying?
That is strange, because i use AOE spells mostly in tight spaces, where i can create an obstacle for enemies to crowd in, which is harder to do in open spaces when the battle is already in full effect. I love friendly fire, it just makes the combat much more pale when you can throw anything but the kitchen sink without thinking about how that is going to effect your party, i think that should be for the easy and story modes.
For me, all of this is for the benefit of the game. What you call removing I call improving what's already there. Combining Endurance and Health into one, getting rid of 2 party members to enhance the AI and combat, and getting rid of friendly-fire on permanently to give people a choice as to whether they want it or not.
But your whole point of improvement stands on the notion that the devs will somehow make the A.I much better, without that they are just throwing out extra complexity to make their job easier, not to enrich the game with many more options. While i would love that to be true and would forget about these deletions of some parts of the game mechanics, there is nothing to indicate that it is so, at least not that i have seen.
It also makes all healers in the game completely worthless, because 99% of the time it's far easier to just let someone be knocked out, than to waste a high level spell keeping them on life support.
We have very different playstyles then, because my playthrough on hard was very dependent on healers, i actually don't see how you could kill the adra dragon on hard without them. Many battles on hard take very long and healing spells are crucial, at least for me. Although i guess on normal or easy it's a more useless option because of the quick battles.
If they wanted to make Tanks better at tanking than wizards/rogues, then why didn't they just make them have differing amounts of HP, so they die less, rather than creating a separate health bar for them?
But they do have different amounts of HP? My fighters has 500 hp with 110 endurance and my buffer has 330 hp with 80 endurance. Have i misunderstood something here?
Anyway, one of my main problems with PoE is that you could never really create any unique characters. Every character you played would always be basically the same, the only real difference being whether they hit there enemies with magic, arrows or swords.
Like, how much more unique would each playthrough be if Ciphers had the ability to read minds, or change people's thoughts during dialogue, or if Wizards could read runes that nobody else could, or if Chanters could use knowledge of folk legends, ect.
Instead, they just each seem like generic combat roles, rather than having any tangible impact on anything else in the game.
Am i missing some games? I am serious, i don't remember any rpg's having that depth, well maybe Planescape Torment. Which games have these and do they have linux versions?