I've played Quan for hours on end this past weekend, so I'm going to share most if not all my info.
First off, I think he should be played as a rush down character. He's only got one projectile, and despite the fact that his trance wins any trade you will get punished for a blocked trance closer than 3/4 screen. If you want to try and trade I found it best to throw it out at peculiar times, not when they expect, also don't spam it (trying to brake that habit) if you get close to sweep/jip distance you can trance for AA at a certain time but the timing has to be spot on. He's built on meter, obviously, but without it he can still do massive amounts of meterless damage. Sometimes he feels like a comeback character too. It's all catching them in a trance or B3 1+2 or string into trance so that they will break, like using other characters and catching people in combos, projectiles, etc. Once they've broken and I catch them again it's usually an enormous amount of damage that they are punished with.
So, since I consider this character best for rush down there are a couple things I want to take a look at.
And as a side note if someone would like to find these properties on block it would be awesome.
B3 1+2 : (low, medium) It's probably the best string, and when it's blocked every once in awhile you can throw in an uppercut afterward to catch people jumping.
B2 1: (high, high) very good at punishing blocked teleports (that ball spin looking hooplah), the combo I use and I've seen been used is B2 1 B2 1 112 trance 11 skydrop into rune trap and mixups.
F1 2: (high, low) I've been debating the use of this for multiple reasons. First off, it's start up is slow, and it's very noticeable, almost every time people see it coming and think (time to block low.) The only time I really use it is to finish a meterless combo with F1 2, 1+2. Although F1 can be used after an air to air punch, into trance, trance, 11 skydrop rune trap or mixup.
B3 3: (low, high) I have yet to use this consistently, but I will try it in upcoming matches.
B1 1: (high, high) I've tried to use this as an AA with not much success, it's got good push back combo wise, I'm not 100% but I think after B3 1+2 you can get 2 trances.
212: (h,h,h) awesome, string used in rune trap, I've also used 21 throw to end a rune trap with no meter.
I use most of these strings in combos, mixups, and resets.
AA: uppercut is the best answer imo, trances can sometimes catch people, and also NJP, B2 1, B2 1,(or maybe just one, will test today) 112 trance, 11 skydrop into rune trap. I've also tried backing up and doing B3 1+2 but it's risky and tends to whiff.
I'm going to try and see what block strings I can come up with, because I think they will be useful in his rushdown, as apposed to throwing out a B3 1+2 most of the time.
Also, I've had people try and jump out of the rune trap, which causes them to get caught in 212 which I can trance afterward straight back into rune trap after 11SD. Although, sometimes only 2 hits and the rest whiffs.. any advice on this?