Just a few ideas relating to this.
20.a)Sentry bots and other robots (Mr.Handy and others) that were redesigned are replaced with their Fallout 1 and 2 counterparts.
It could potentially be argued that robots in New Vegas don't look too different to there original forms.
Like, for example if you look at Sentry Bots, the only noticable differences are that they have four legs instead of two, and wheels instead of walking. There weaponry/heads/toughness correlates pretty much with the 1 and 2 version.
As for Mr Handies, if you ignore that they suddenly lack a couple of arms, there models have very little difference.
Alternatively there is a mod in the works to make a classic style Mr Handy here
https://forums.nexusmods.com/index.php?/topic/276970-classic-mr-handy-anyone/. It's not finished yet so it's not much use.
16.Also Mines in general, can not be disarmed by jumping on the them and pressing E, that is just ... I want to say stupid, but I think it is understatement.
Every Fallout game has a lot of faulty mechanics. 1 and 2 allowed you to inject enemies with hundreds of Super Stimpaks and then watch them die slowly as they all wear off.
I think this would be too complicated to actually fix, so it might as well be dismissed as mechanics.
23.Fire ants that breathe fire are explained in New Vegas by eating a lot of gunpowder from military trucks.
If this rewrite is assuming that Fallout 3 never happened, Fire Ants don't need to be explained, since this would be the first game they appeared in.
22.Gauss Rifle, this one deserves a separate point. The gauss rifle from Fallout 1 and 2 is back, and the variant we see in 3 and New Vegas is either a prototype, a separate model or just removed.
Honestly, the Gauss Riffle just looks like a slightly graphically updated version of the classic one. You just need to replace the Ammo-Type and its settled.
19.a)Power Armour Training Scrapped, power armour can be used without one.
Here you go
http://www.nexusmods.com/newvegas/mods/59489/?