I love the idea of unbuttoned jersey, but it would require a bit in the material physics to get it looking right. I'd love to get that oversized jersey look that Manny started in Cleveland, or getting the fit of those old 80s jerseys (which are a totally different cut to the current jersey - they tapered much nicer in the Rawlings days).
I'd love an option to have fitted sleeves like Sammy Sosa wore.
Necklaces are in 2K's game, so I think it's possible.
I'd love to see different style bats...but hey... things are just amazing this year with all the editing, can't wait to get at this.