I'd like to see:
1) Battle tweaks:
Increased enemy aggression, increased enemy damage, decreased enemy HP. Disabled minor QTE, and auto-completing unavoidable QTE.
2) Music:
Changed music files at least. Easily accessible method perhaps, so custom sound tracks can be made easily. Preferably remove normal badguy 'battle' music triggers except for bosses and mini bosses.
3) Remove shaky cam / snow on lens effect.
4) Change sub weapons:
Change the item drop imagery to hearts, even if it means just replacing every drop model with the same thing. Curse of Darkness had a nice heart design if I recall, with the metal frame around it, giving it a silver color and a red inner heart color. Maybe different colored hearts for each weapon if you can't make it so they all run off of one heart count. Red (inner) and silver (metal frame) for knives, green and yellow for fairies, blue and gold for holy water, and purple and black for the dark crystal.
5) Alternate costumes for Gabriel. At least a Leon, and Trevor from the PS2 titles. Hell, as much as I hate to say it even Judgement's shitty designs might be nice to see.