taaron i think u can try lower than 63, those mids are quite good, plus your door is well prepped already. try la 55 or 50 or 45 and see how it goes on high volume...

grinders set to hpf when u are using the amp formidrange/tweeter or component set
set to lpf when using amp for sub
set to full when using 6x9 coaxial, the 2 way 3 way type sepakers
bass boost is like an eq, but fixed frequency, like 80hz boost your sub if u need, if not dont boost
sub level: not sure about this, could be the same as bass boost
gain level: this is important, its like a volume knob but cant put so high, can damage your speakers.