2. They never addressed why Ant-man couldn't just shrink into Thanos and kill him that way. Its been one of the biggest things going around as why not just do this so I figured it might get a line about whey it wouldn't be possible.
Why would they? It was a stupid fan theory from Reddit that blew up as a meme. Regardless, the movie was about reversing the snap, not killing Thanos. And I'm pretty sure Thanos' body is too strong for that to happen, anyway. Ant Man would have been annihilated if he had tried it.
3. Was hoping for the arrival of the dusted to be a little more epic, but barely noticed they were there other than Parker.
Doctor Strange held the water back, Black Panther helped Hawkeye/Ronin with the Infinity Gauntlet, Falcon had a nice moment where he impaled an alien with his wings, Scarlet Witch whooped Thanos' ass so badly that he called for "rain fire," Star Lord got kneed in the balls, etc. Everyone had some type of moment, not to mention the most epic scene in the entire MCU when they all showed back up.
4. Had hoped that Doctor Strange would have gotten his revenge on Ebony Maw and they never even crossed paths.
It wasn't part of his 1 in 14 million outcomes to get revenge on him, and I don't think Strange is the type of guy to seek revenge anyway.
6. The girl power scene actually caused my theater to laugh out loud. Look, most men in this day in age get that women rock, but you don't have to cram it down our throats all the time because it looks silly.
Highly doubt they were laughing, but we all hear what we want to hear.
8. What the hell happens to Sharon's family now and Cap used to make out with her grand daughter. Is she now wiped out of existence.
Russos have said that Cap's new life with Peggy was an alternate timeline.