Neutral Game:
Feng's main space control tool is iWS1 out of his command dash. This mid is i13 (more like i18 with input time), has great range and is only -1 on block. On hit, it's +5. Fairly fast whiff recovery, and extremely variable spacing. Based on seeing your opponent whiff or dash in, you can try to confirm iWS1-2 for 26 damage off it. This move is extremely low risk, and mixes up QCF1 if done more slowly.
QCF1 is a low shoulder that cannot be low parried. It's -14 and deals 23 damage. On hit, this has considerable pushback, resetting to neutral. This is a high crush that can often evade mids, and a scary counter hit launcher.
The command dash these moves come from is a high crush if you hold DF during it. The flaw of QCF1 is most mid mixups for it have poor range. This matters more because the opponent can react to seeing you CD, to guess that QCF1 is coming.
FF2 is Feng's demon paw. At i18 it is slower than standard, and without a CH property, but has better range compared to most moves of this archetype. Wallsplats. Good for hitting people at a range where they think they're safe in moving forward.
F4 is an i18 high launcher that can enter backturn. F4-3 will beat out slower whiff punishers and people rushing into your space after it whiffs, guaranteeing FF3 for 50 damage. F4-4 is a low launcher with extremely fast high crush; this will kill Mishimas trying to whiff punish with EWGF, even if they react fast.
In pushback situations from poking, a backdash F4 can catch limbs being stuck out towards you. When you've baited an opponent into dashing into your space, it's also good for catching them in the act.
Your opponent will want to do this, because of...
B3+4, or Back Kenpo. This is a backswing stance akin to doing 1.5 backdashes. This gives you access to a fast & chunky whiff punisher in KEN2, your main move out of Kenpo. KEN3 is a slow mid launcher at i20. KEN1 is a complimentary power low, but be aware that all KEN moves bar KEN4 are extremely fallible to backdash.
In combination with Feng's high crushing command dash, this stance gives him strong space control without the risk of actually attacking.
Pokes:
QCF1+2 is an i16 (i20 with input) mid headbutt with decent tracking but stubby range. This deals 21 damage on hit and is +4 to +5 force FC on block. While the pushback makes DF1 whiff on backdashers, this offers excellent pressure. It also counter hits for a KND and guaranteed FF3 or headspring.
DB3 is an infamously annoying i16/i17 high crushing low. While it's -15 on block unless at tip range, it's +4 on hit (Feng in FC) and has a 30+ damage CH property, as well as tracking fully both ways. This locks down an incredible amount of options. After this hits, WS4 tracks step fully both ways.
B4 is another lockdown poke. This is an i12 safe mid that tracks fully both ways. This would be insanely oppressive, but it has considerable pushback and is only +2 on hit. If it hit close, D4 or DF4 are the fastest moves that will connect with backdashers.
B1 is a nerfed but still worthwhile i10 high CH tool. On CH, this guarantees a dash B1+2 shoulder for 44 damage. -10 on block since S2, some tracking to the left.
DF1 is an i14 mid that's +0 on block. This means B4 beats their DF1 and B1 CHs jabs. On CH, this causes a +36 stun, allowing guaranteed hit tech or a launching SS4/SS DF3 mixup. Sharp hitconfirming will get you everywhere. Depending on how shallow this hits, you can back kenpo a LOT of moves after this. Very poor tracking to L, Feng's weak side.
DB1 is a high evading i16 mid poke with minor backswing properties. This will evade most jabs & magic 4s but is situational. Long range. Follow-ups can be whiff confirmed if you're sharp. Enough tracking to hit people trying to step-duck DB3.
D2 is an i20ish -12 -1 low poke that leaves Feng in FC. On CH, can get CC stomp or, with execution, CC D4-1+2 pickup for very strong oki. Situation on hit isn't very strong, as Feng's FC options can be SSL pretty universally. This high crushes for not only its startup, but also its full whiff recovery. Can be used as pseudo keepout vs Mishimas. Due to pushback, CC back kenpo can make a lot of things whiff.
UF2 is a mid poke with strong auto sidestep. Dies to the smallest SSL. CH stun with very strong oki, but often misaligns on CH and doesn't get it. High pushback on hit or on block that renders it safe vs almost everyone.