After I looked back at DAves pic I figured out what you were talking about There are engines with built in water/fuel separators? I know they've got normal fuel filters (Like both of mine do).
Why would you need dual tanks? One line from the tank to the fuel separator, then two lines off the separator to both engines. That's exactly how mine is run. No issues running both engines at the same time, etc.
Dead simple.
This is a good time to run a fuel/water separator... That's the setup I run with our Yami 115 and the T8 kicker. Nice and clean, plus a little bit of added protection.
So it sounds you've found a spot, keep at it. Gotta remember the water is cooold, gotta keep those presentations nice and slow (Easier said then done though, lol)
If you're getting 8-9 years out of a normal lead acid battery that will use any charger, why bother with AGM? What does AGM do better? From what I've been reading, nothing.
I've killed the battery on my main I think twice.. Battery doesn't have enough juice to start the big motor, but it will start the kicker without issue. I'll troll around at WOT on the kicker to charge the battery just enough to get the big motor going. I haven't had this work around fail me yet