I agree that Thor and Valkyrie would've made an interesting romance angle, but Hulk and Nat??
That doesn't work at all, imo. It came out of left field in Avengers Age of Ultron with not even one scene showing their budding romance.
To be honest, i thought Nat was just putting that seductive whammy on Hulk and didn't have real feelings for him. I thought she was just a means of control but i guess she really likes him

.
And that bullshit they say to calm Hulk down is dumb as hell. It works when men say it to him

and even as a pre-recorded message

.
Movie itself was ok. I'm a big Thor comics fan so it annoys me to see him played as a joke. I think i like Dark World more than Ragnarok, but the first one is definitely the worst of the 3. The way they nerfed my boy Destroyer

... this dude normally wrecks Thor and the hammer has no effect on him since he's a creation of Odin's.
But that's another topic lol