cutting the top of the main stem of a mother plant and other wierd questions

What would happen if I cut the top of the main stem, maybe 3 inches of it from the top.?

ALSO what would happen if I straight up pinched the new growth thats surrounding it? would it give smaller buds?

Also your theory on removing 'popcorn' buds.. does it focus its energy to the bud sits on the outside?

aw cmon guys, BUMMPPPPPP

cutting off the top of the plant is just topping so it would make two or four main growth shoots

and pinching the new growth is supper cropping

lol what if the plant is like over 2 feet though?