This is easy, needs to go:
1. Making the film about two or three characters instead of the whole team.
You mean, in the way that Avengers did? Focus on a team dynamic? Yes, I'd like more of that. And more camaraderie/dynamics between the X-Men when they are 'off duty' too.
2. Rogue! Give us the real deal or leave her out. Same goes for other powerful characters. If you're afraid to make them powerful then don't use them or get off the movie.
I think we'd all like to see a real Rogue. Unfortunately, she took the cure in X3. Fortunately, it was shown (by Magneto's reaction in X3) not to work and (by Beast's reaction in First Class) that such a cure might in fact enhance/advance the mutation.
The answer: show Rogue absorbing the powers of a dying mutant in DoFP. Not sure they can use Ms Marve/Carol Danvers, as in the comics, but they needn't even name the character she absorbs the powers from, just have some superstrong, flying chick who gets taken out by Sentinels. It would be the dying woman's last gift/legacy to help the remaining mutants fight the Sentinels by giving her powers to Rogue.
3. Making Magneto look like a weak old man instead of a bad ass who can take on the whole team.
He didn't come across too weak. And now we have Fassbender, he isn't old either. All we need is for Fassbender to stop slipping into an Irish accent! His father's German for God's sake, it shouldn't be difficult to achieve a European inflection. They could bring in David Hemblen, who voiced Magneto in the 90s animated series and almost played Magneto in X1, to serve as a voice coach. Hemblen's Magneto accent in the animated series is SUPERB!
Yes, enough of that already!
5. The horrible costumes. It worked in The Matrix, but this is X-Men not Neo and Trinity.
First Class is already moving away from that and if the films carry on in the psychedlic 60s and 70s, there is scope for more colourful outfits.
6. Mystique being portrayed as a total *****.
Yes, she needs more dimension. First Class has begun to do that. She's also shown in the animated series as having more story and character.
This is hard. There are not very many things that I like about the first four X-Men films. Needs to stay:
1. The government and most normal people being afraid/against the mutants.
Agreed. And let's see why they are afraid and how they show that fear.
2. Giving each character a purpose and a scene to shine. Wolverine from X2, Storm and Juggernaut from X3.
Presumably, you mean the mansion raid in X2 showcased Wolverine? Not sure about Storm in X3, she still wasn't quite right - too much attitude. And Juggernaut didn't come off too well either - the 'I'm the Juggernaut bytch' line was atrocious, the rest of it too light and jokey and not scary enough. Watch the cartoon for a better performance! Needs a more powerfully built actor and more menace!
3. The bad mutants against the good mutants. The was best shown in X3, which is the film that I have the least problems with.
Yes, a clash between good and bad is needed through properly planned-out battles.
You're right. The opening came from Singer, but it had a purpose this time. Eric going after Shaw was brilliant. In X-Men it seemed pointless, it was like it was only put there because Singer is obsessed with that stuff.
I disagree it was pointless. McKellen's Magneto referred to his past later, at Liberty Island, if i recall correctly. It showed why he hated humans and how, ironically, he was becoming the thing he hated.
And the part with Wolverine was the greatest cameo on film... ever. I liked seeing Rebecca, but it didn't make sense.
Rebecca Romijn, especially with long blonde hair, does look like an older versiion of Jennifer Lawrence, so it worked fine, I thought.