The pushback on Paul's i12 shoulder prevents Feng Wei hopkicking it. Feng is encouraged to step-guard to block B1 and evade shoulder, where possible, as his DB1-4 punish does 35 damage & a CH shoulder does 36. This makes for a weak deterrent.
Paul's i10 punish is poor, so B1 is above average in this matchup.
Hit by Paul's B1 at closer spacings such as after range 0 Feng DF1. Paul B1 also covers Feng DB1, step, and UF2, so he has reason to use this often. Paul's F1+4 auto-sidestep shoulder also covers both this and Kenpo. Paul's i14 D1 also hits kenpo pretty well, but he's very vulnerable to kenpo at further spacings, for example after hitting his QCF3 at anything but the most absolute range 0. At these spacings he could use iFF2 to be safe from it.
Kenpo evades his D1+2 shoulder very consistently, his DF2, his DF1, his UB2 homing move. All but the DF1 are also quite poor on whiff and you may be able to KEN3 them on reaction.
In neutral, Kenpo makes it hard for Paul to get an SS3 mixup going. His QCB2, deathfist, etc, are terrible on whiff.
Feng Wei's strong 1 jab hitbox will CH Paul's D1+2 and DF2 consistently. The same is true of Feng's B1, making it very useful to deter these moves when you have a read, risking only a mediocre i10 punish. Paul's B1 will hit a Feng DB1 consistently, so it may be better to use CD iWS options instead, with a timing that punishes B1 but allows DF2 to hit you crouching.
Paul's i14 DF1 trades unfavourably with Feng DF1 at neutral frames, leaving Feng at +30 with a bit of pushback.
Punch sabakis can cover Paul's 1, B1, DF1, D1 and DF2 simultaneously with correct timing, making them worthwhile options. This includes iWS1+2 if you want to be safe on block.