Is my amp too far from My Battery in My SSV

I have a 2002 Launch SSV with 2 wake designs tubbies (2 (150 Watt) Bazooka Marine Speakers in each), and 2 wake designs seperates (with Rockford FOsgate Punch Speakers) on the tower, and 4 MB Quartz 6.5" seperates in the boat. I have an Audiobahn A275 HCT driving the 4 tower speakers which are wired in parrallel, and I have a Sony 75x4 amp driving the mb quarts both amps have their own capacitors. The previous owner of the boat installed the system and pulled 2 runs of power wire to each capacitor with matching grounds, but the wire looks to be 6 guage industrial type wiring instead of amp wiring. The power and ground wires run from the left rear ski locker, around behind the engine, to the kick plate which creates teh false wall at the drivers feet. When the engine is running or the blower motor is on I can hear the engine sound through the tower speakers. Should I rewire with 0 Guage wire from the battery to a splice block and run 4 guage for 1 foot from the splice block to the capacitors? Where should I ground the capacitors? Is it ok to run another splice block and use 0 guage from there to my grounding point? Also is it ok to run my tower speakers in parrallel off of the audiobahn amp (since rnning at 2 ohms doubles the output will it blow my tower speakers?)? I am open to any suggestions.