You have a much better chance of getting your temps lower by blowing the air off the fins rather than sucking them off. The fans meant to blow, not really suck
Yes but theoretically if your air flow is geared towards better with it sucking...
I have dual panaflo inlets at the front of my lian-li pc60 and 1 inlet on the top (I reversed the fan direction) the exhausts are 1 80mm on the rear and of course through the psu. If the CPU fan is sucking, the air should be cool flowing through it, cool the fins and then go straight out the exhaust. With it blowing, logically the hot air then has to travel much further to get to the exhaust AND the exhaust and CPU fans are both blowing in different directions...