flow problems

[spikehs]

I am looking to push around 15x (or more if possible) the tank volume.....

Well this is my "current" plan (it'll probably change again ). I am going to plug up one of the holes on the back and put a valve on the other, and use that to drain the tank for wc's.... then I am going to place the pump inside the sump/fuge and use pvc or loc-line to plumb it to the 4 outlets (can't decide between the 2, any opinoins?)... anyone see any problems with this plumbing setup? thanks.