OK, No 1 you could go for this: Start with full gold, buy Mjolnir, Linken (or change Mjolnir to MKB, up to you) then get Alacrity
and something else as your main spells (ghost walk could be recommended)
No. 2: Nuke him to death in the early stages, out level him, do what doomsheep said, and make him miserably useless (just finish the game quickly)
No. 3: PICK A DIFFERENT HERO!
No. 4: As soon as you start the game, go to his computer then push the small button under shutdown, which is Sinisterly called the "Reset" button.
EDIT: And no, Troll cannot win against Void, once he is under Chronosphere he'll sit there helplessly watching his ZOMGWTFBASHPLUSDAMAGE?-ful death, Try Broodmother