One way to get more relaxed about this is to remember that the only thing you cannot do easily after you've launched is work on stuff below the water line that keeps the water out. If seacocks need servicing, get it done then close them, make sure your stuffing box is packed for rudder and prop shaft if applicable. Bottom is painted. Knot log is removed and the plug is in place so it won't be broken by trailer or travel lift straps. If you need to immediately motor to a slip or mooring after launch, run the motor on the hard with a bucket of water on the intake or muffs on the outboard to insure it will fire up. Do all this before launch day.
On launch day, when it's wet, still on the trailer or travel lift straps, lift the floor boards and look for leaks. If you can get the intake in the water, start the motor. Everything looks good, remove travel lift straps or trailer and off you go. Don't skip this step, don't ask how I know
Everything else you can do in the water....that said if headed to a mooring, I'd usually put everything I could on board before launch just to save the effort of dingy trips.
Still too cold here even think about splashing! Welcome to Cape Cod Spring.