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.