hey man, the pinching is kinda risky, it works but it may just damage ur plant if its done at the wrong time. same with topping it. they should both be done early on so the plant splits befor its too tall.
the sugar thing is probably the best bet for u at this stage, the plant takes the extra sugars and uses them to make the buds the way they would make it themselves... just faster. and if u wana make the stalk and the nodes stronger for supporting bigger buds you should get a small table fan or a small oscilating fan and just have it bowing on the plant enough for it to tremble, this will make the plant react the way it would to wind and bulk up the stalk so it doesnt fall over in wind.
if u are going to start another crop n e time deffenatly top ur plants. just wait till they have about 2 or 3 leaf layers and snip off the top. the nodes right under the popped top will split and grow into 2 seperate plants, its like 2 plants in one.
oh and one more thing. this is what i do n e way. when u are getting into the flowering schedual try to trim off a few of the big fan leaves, careful not to take off the new node coming from the base of the leaves, thats were the budds grow. this will concentrate the plant growth into the buds, growing bigger denser buds.
hope i helped.
PEACE