I've had a look through and watched a few runs already. I know PS3 is the fastest version for a decent amount of the categories, but I was curious about which ones would be best for running on PC. Okami is a beautiful game and I would love to get into running it.

PS3 is the best for NG+ without question, for the NG categories PS3 is one of the worst actually. For those categories PC is definitely the fastest version to run on.

What's the estimate for a NG run on PC? I know certain glitches or exploits aren't possible either due to it being NG or them being patched on PC, but I would enjoy running the game either way.

NG Any% would probably be 4-5 hours long on your first few attempts. It's an enjoyable run though, I'm learning it right now as well. PC is the fastest version of the game for NG categories, the major glitch that's patched on this version (KT Jump) is only relevant to NG+.

Is there an optimised route for NG Any%? And is there a NG 100% or no?

There's no 100% category, but there is All Brushes and Top Dog (All Achievements). As for routes there's no detailed guide or route map for NG Any%. I'd recommend reading through Cyd's notes (www.speedrun.com/Okami/guide/k5lda) while watching his PB (www.speedrun.com/Okami/run/z5ow8wey).