If they don't respect raises, raise bigger and raise less until you find a balance. 4+1 is a guideline, not a rule. How they play post affects the rest of your starting hand criterion.

No way they can play "good" if they're that short. If they're behind you, just stack off with almost everything that you're opening (assuming they're not uber tight). You should only be opening pretty big hands from the first two positions anyway. If they're in front of you just be aware that they might limp/push if you raise and plan accordingly.

If they call with position:
Depends on how they play. If they rarely call a push I"m pushing every flop I miss. If they're almost always calling I'm pushing anytime I have TP+ a big draw, or two overcards. If they like to fold I'll probably check if I hit and let them push they're chips in.

If they double up and stay I would expect them to continue to stack off light on flops, just pay attention to what they do in other hands (although it sucks because sometimes you're the only aggressive person at the table)