I have exactly the same boat. Same color and everything. I mounted two 250hp Evinrudes on the back and rigged up a steering wheel. It tops out at around 145. Lotta fun.
For a family named 'hole' it would make sense to have the 2 bow sprits turn around and face the other way, I would think. I like what you did to lower the roof for stability. I am planning to use a free 19' hobie hull and do an electric/solar boat. Looks like you are having so much fun!
Why not leave the mast in place to sail it when wanting to. It's much more fun sailing the H-16 rather than driving it like any other motor boat! That canopy must be easy to lift off and set the boom into place on the mast and it'll probably go faster with wind rather than gasoline. Free energy and so much more fun!!
Hard to get munched!! The prop is behind the drive so one would get knocked out of the way before getting hit, but as I mentioned above, a prop-guard would take care of the possibility of getting cut! A net is a good idea but one would have to design it, as there is no such standard piece of equipment that I know of!! It would be easy to install though, without having to install additional hardware that would require drilling into the fiberglass pontoons.
As soon as time permits and the weather is nice, I will get the Hobie 16 out of the barn and set it up for you and show you pictures and videos of how I constructed the roof and the mounting.
My dear friend, the motor is placed in such a way that I can also sail. I steer with the rudder not with the engine. For example, if I want to go out to sea in the morning, there is usually no wind, then I use the engine. When the wind comes at about 10 or 11 o'clock, the engine is folded up and then we sail. But without a roof, the roof is good when the whole family is on the cat.
The emergency switch is with a string on my wrist. The motor stops immediately, only the boat continues to float. the nice thing is, I can sail and drive with the motor at the same time. when the motor is folded up, the motor does not touch the water.