On handwriting Pure preference will probably be for my right and it is noticeably worse (though as above my right hand was never good) but still enough that I can take legible (to me at least) notes fast enough to count with the left.
Can solder, use a scalpel, slice vegetables, knife and fork, grab a torch, walk the dog (a large German shepherd with a tendency to want to chase rabbits, me living surrounded by them), type one handed, use game controller one handed, punch, grab, climb, lift... with either and that usually goes down to ease of use -- was desoldering some capacitors the other day and could have spun the board 180 but swapped hands instead.
My shooting is not as hot with my left with a pistol as I would like but that is also a serious lack of practice. If doing the point at something and close your eye (whatever one lines up is the dominant eye) I am neither eye dominant -- right eye does right hand, left eye does left hand.