Re: clearing i/o when removed from water?
NEVER...NEVER...NEVER "Dry start". That goes for outboards also. The impeller is rubber. The rubber will QUICKLY(seconds) burn and distort/melt the impeller vanes without the water cooling it.
Don't worry about anything at the launch...you'll be one of "those" boaters who spend too much time in other peoples way. I usually pull the bilge plug, strap the transom and go.
When I get home...depending on the condition of the water at the landing(some of it gets pretty "gamey"!) I will hook up the muffs just to run clear, clean water through it. Unless you're in salt, I wouldn't worry about draining the block after every use either.