Currently I have 2 case fans that use what appears to be 4 pin molex that comes from the psu for power. My motherboard has 4 pin slots for power that differ from the cables my case fans currently use and are not currently being used. Can I replace these fans with ones that plug straight into the motherboard?
Depending on your MB, there are probably several fan headers on it. You can plug your fans into the board or the PSU. The CPU fan should be plugged into the CPU fan header. You can purchase cable adapters if needed.