Character improvements!:
Kokoro: Tracking!
Ryu: Better frame data!
Lisa: More speed!
Sarah: Hella nerfs!!
Those are the most needed buffs for the characters.
lol Ryu's frame data isn't too bad, actually, though 4PK is dumb as hell now. What he needs is more lows and mix-ups.
I'd also add:
Akira: restoration to DOA5 vanilla status.