For all of those, there is no one-size-fits-all solution. I've used some hull cleaners that will clean the skin off your hands also! They are by far the best thing to use if you have a really bad hull, but they are not something you would ever consider for normal maintenance. No need to use a jackhammer to pound a nail into the wall. Same goes for outdrive, you could say the best way to maintain it is a sandblaster and paint booth.
Anyway, my recommendations... For a medium to slightly heavy duty hull cleaner, look at 'Safe AR Hull Cleaner' (wear gloves!) I then hit the hull with 3m boat wax. For mold and mildew, its far easier to make sure everything stays dry, and prevent the mold from growing in the first place. A diluted mix of bleach and water works great to kill existing mold. As far as engine compartment, simple green, hot water, lots of elbow grease.
