I agree with everything, except the Steve being the butt of jokes and the Thanos scene as cons.
Eh, I can see why Cap works as a good target for Team Banter because of his personality, but he's supposed to be the stoic commander of the Avengers, not their verbal punching bag. With Joss Whedon, Iron Man seems more like the leader of the team than Cap.
The Thanos scene was just kind of shoe-horned because it served no purpose, we knew from the Avengers 1 Post-Credit scene that Thanos is up to shit, and we know from GOTG that he wants the Infinity Gauntlet, it just served to further needlessly hammer the point of "HEY GUYS DID YOU KNOW AVENGERS 3 IS THE INFINITY GAUNTLET?" which we knew already.
It should have been something that lead into Civil War, like Zemo or Spider-Man. Maybe even a Doctor Strange related scene.
Cap felt like the leader, but he wasn't a douchy leader like Cyclops, he was the one who kept everyone grounded and focused, he even served as the foil of Stark's mad scientist shtick. To be honest I find the "stoic leader" archetype to be extremely boring, with Cap it felt more like they respectd him, but they were close enough to give him some shit for his more boy scouty tendencies.
The infinity Gauntlet was stated to being kept in Asgard, so Thanos getting it means that some shit is going on in Asgard, Thor Ragnarok might even be his first appereance proper.
One thing I personally wanted to see, was cap lifting Mjolnir. But I get that that would've shifted focus from Ultron in the scene, the scene being his introduction after all. But then again, the whole movie shifted focus from Ultron.
Anyone else felt it weird that a female jarvis replacement appeared out of nowhere?
For the record, possible SPOILER territory/theorizing/movie critiquing ahead...
I don't think the Thanos scene was shoehorned in. The first credit scene in
Avengers showed Thanos, then didn't address him at all until
GotG. It simply showed who was pulling Loki's strings and got the hype going for
Infinity Gauntlet/Wars while the second one showed that Thanos was somehow aware of, and possibly even influencing things going on during the Ultron event. Now he will be playing a more direct role as opposed to using pawns.
One thing worth mentioning is, the Gauntlet that was shown in Odin's vault during
Thor had gems in it already, so the one Thanos picked up is different, at least it seems to be, with Feige even going as far to say there are two Gauntlets. Maybe one is just for looks. Either that or the Easter Egg in Odin was just for fun. It should also be noted that one Gauntlet shown was for a left hand, the other a right. It is also possible that Thanos was let into Asgard by Loki to receive the Gauntlet, but he may have already had it in the first place.
As far as the team leader comments, Cap leads in the field, he gives orders and handles tactics, while Iron Man handles the technical stuff, like when he busted through the shields at the Hydra Base, or when he figured out how to stop Sokovia from destroying the planet. Ultimately the Avengers work as a team. Iron Man has often lead the Avengers, as has Captain America, and Thor. That is why the call them the big three. The Justice League in DC has a similar concept.
I think Cap lead perfectly fine, the problem is, Stark is doing his own thing, making murder-bots, causing mayhem to a certain extent, and now he quits the team in a sense at the end of
AoU. So Civil War looms, what role Stark will play is questionable. He was Secretary of Defense in the comics at one time. Stark has a lot of personal demons after
AoU, even more so than before.
As for the "female Jarvis replacement" Friday, she is actually straight from the comics!
http://marvel.wikia.com/Friday_(Earth-616)
The Veronica reference is an Archie comics thing. Betty and Veronica. Banner was with someone named Betty and now he made Veronica. Whedon is weird with his Easter Eggs.
Vision lifting the hammer must be because he was an Android, well, and he has an Infinity Stone in his forehead. Cap lifting it would have achieved nothing in the movie plot wise, but if the shit hits the fan and Thor is down, I guarantee he would be able to lift that hammer.