First situation is a raise every time. You need secure your position against these bad players and take the lead with a hand that is likely best.

I don't like to raise w/AJo in the blinds. AJo OOP in a multiway pot gives me nausea. The only time I raise in the blinds is when I'm reraising a possible late position steal from the small blind. AJs I'll raise sometimes to build a big pot, as this hand plays better in a big multi-way pot.