Also, about Fox's jab lock, I don't think the crouch is needed with him. I have tried testing it by holding down-away at the "3 ticks from 8 o'clock" position, but doesn't seem to make a difference, seems to be 20 frames difference in between with both methods. So there's no difference between tapping A -> A or doing this while cancelling the jab with crouch. It might just be that I'm not fast enough though: I'd appreciate someone helping me out.
It is worth noting that if you hit with the jab while your opponent is close to Fox's body, they'll just get knocked behind him as well. While this is obviously not going to trap them into another jab, it can lead into U-tilt, which is guaranteed anyways (U-tilt comes out in frame 5 iirc) on anyone who's not a fast-faller who can shield or floaty enough to jump away.