I like social links They should absolutley keep those :(
But I do miss demon negotiating too. The reactions of the demons were always hilarious to see. (I remember trying to seduce a demon as Ginko, to which he replied something along the lines of "I don't want you horseface." PFFFFFFFFFT!!) However if they do bring negotiation back, they should make so its less of a hassle.
Also it would be nice if they brought back skill cards. Those saved my butt in the final battle with Nyx. Lastly, I liked how in Persona 2 IS you could give each and everyone of your characters whatevever persona you chose. It allowed for some interesting customization and made things more interesting. I was a little dissapointed when I picked up P3 and discovered I could only change the persona of my main character (it was a small drawback, the game was awesome either way).
A weakness scanning that is actually useful. I don't mind it with Teddie since he's really just observing and memorizing stuff, but come on, Rise.
Her skill upon Persona Evolving isn't that useful either. I'd prefer if she can actually reveal a weakness, even if it's one-by-one instead of telling us but never recording it. It gets worse when fighting a group of enemies of different types and she doesn't tell which one she's scanning. --- The average intelligence of a fandom is inversely proportional to its size.