>it was like leaving game 6 after the home team had a chance to end the series, but they lost and now you know they gotta go on the road for game 7.

Pretty much. Part 2 is for all the marbles. BP didn't really hurt (I think they should have wiped Okoye, which may have stung a bit harder, as it's more believable they write her out than BP, though not really because BILLION DOLLARS) but Pete did, even though I know he's not dead for long. I think the deaths work in the moment for just about everyone, but then fade for comic and MCU junkies. For everyone else, they still stick. Listening to the people that leave the theater, you can tell

While I posted this over in GD, if I had to pare down the movies to see for someone that has never seen a MCU movie to get who's who and what's going on, I'd say:

Avengers 1 (introduces the team as a whole)
Avengers 2 (introduces Vision, more info on Infinity Stones)
GOTG 1 (introduces the Guardians, more Infinity Stone info, more Thanos)
Civil War (Bucky, Black Panther, Spidey, why they broke up)
Ragnarok (Doc Strange cameo, where have Hulk & Thor been, sets the start of IW)

as RJCC said, you CAN go in cold and figure out who does what on some level, watching these 5 sets the table for 95% of who and what you're looking at. At worst, you could see IW all by itself and still have a better idea on what's going on with 30+ characters than you could with Justice League