few questions
 

Soon I'm going to install my speakers and speaker amp but need help with something, I got one run of 4 awg wire to my sub amp but my 3 way crossover and the speaker amp will also need power wire, remote wire and ground, so my question is is what do I do about the power and remote wires (ground is easy since there are many places to ground from) do I use a ditribution block for the power? But what about the remote? Another question is what is a safe way to run the speaker wire through the doors?

Depending on your total power yes you can use a distribution block on the power wire. For the remote wire you can just connect the three together. Some would use a relay but should be no biggie for three pieces.

For wire into doors - if you don't have factory boots then you might want to visit a pro..