The most Fling damage is Iron Ball.

Is fling a good Pokemon move?

Fling is definitely an interesting option, but it is quite easily outclassed by moves that can inflict similar or better effects, and possibly with more reliability.

Does trick work if opponent has no item?

Trick DOES indeed work when you are holding not holding an item an your opponent is.

What triggers unburden?

You should generally activate Unburden when youre ready to do a lategame sweep or put pressure on your opponent midgame. Since you loose the speed boost after you switch or gain a new item, you have to choose the best times so you can make the most of it.

Does trick work without an item?

Trick DOES indeed work when you are holding not holding an item an your opponent is.

Can you trick the rusted sword?

You cant knock off or trick off a megastone or other form changing item like blue orb or rusted sword.