Teams have started doubling KP with or without Melo; Melo was affording him some extra space for one on ones early, but it's shifted somewhat. So Melo's been less of a boost to dude for sure. I don't see KP being held back by Melo though, stars become stars. I can't really think of any players where I was like "man...he'd be better faster if not for that teammate" but I can think of guys where I thought "he'd have a bigger impact with higher usage (James Harden, Joe Johnson, Harrison Barnes somewhat). Thing is, like I've said before, I just don't think he's shown the mentality lately that would make him comparable to other young cats who attack, attack, attack. When he gets back, assuming fresh legs, I hope he'll look like he did earlier in the season with or without Melo. It didn't matter that Melo was getting his, KP was getting plenty of looks too. Lately, he's settling and at times not demanding the rock. I think it's just been fatigue though.
Not having a gang of veterans around him would make him more aggressive, there's a reason why teams purge their squads of older players when they get young stars and only look to add veterans later on to add stability after the young player has established themselves. If he were out there demanding the rock and taking shots from Melo, how do you think that would be received? He's a PnR type of player, that plays with a scoring PG & scoring wing, he gets the ball but it's not always in the best position and it's not like the Knicks make it easy for him, where are the cuts? Why not use him more as a passer, he seems to be a very good one but that's not how he's used. He's almost exclusively used as a Pick and Pop guy. Playing him at Center will probably improve his offense as there are less 5s that can check him, where as PF's are becoming more mobile.
Getting KP a PG that can set him up in advantageous situations is absolutely the next step. Getting into a spot to draft one of the PG prospects is definitely the easiest way to that end. Looking at the FA list, there's CP3 whose a great playmaker but off the timeline to work with KP long. Then there are a few good/decent all around PG's that aren't really stud playmakers (I'm a big fan of George Hill but he can't stay healthy lately and he's not a playmaker; Jrue and Teague I mean...not exciting names but passable). Those cats are nice pick ups for the right contract but not really long term keys.
Breh, you can't rely on the FA market anymore, the new CBA is going to limit player movement a lot. The only way the Knicks can get a good PG is via the draft, or a really smart trade for a young guy who is stuck on the bench behind someone.