I'm thinking about the timing and the ability of Wes Janson to strip tokens. Firstly: if Wes Janson uses snap shot, is he able to strip tokens with it? For example, Omega Leader with comm relay has just flown in front of WJ crosshair (range 1), WJ shoots with snap shot and takes away OL's evade token or blue target lock token. Is that correct?

Secondly: if an X7 defender flown in front of WJ crosshair, does it get its evade token before snap shot is even used, so that when WJ shoots he is able to take the evade away (assuming that TIE defender didn't spend it)?

Correct, Wes works with any attack.

If the X7 has initiative, it gets its Evade first, then Wes attacks takes it away. If Wes has initiative, he shoots first, takes nothing away, then the X7 gets its Evade.