I don't see that spell leak, the first leak i found was in folder "(LotR-Mini) Creep System" where every trigger which starts with Move, leaks here: Set TempLoc = ((Center of creep spawn sentinel L2 <gen>) offset by (0.00, 0.00)), you need to store this: Center of creep spawn sentinel L2 <gen> in another variable. And now question why you set TempLoc to null after removing it? No need.
Also when you create Special Effect you need to destroy it! If effect is not meant to be permanent then destroy it after you create it.
Sounds leak too, after playing it destroy, no sure if right after playing it but you can check.
Other then that all looks fine maps runs perfectly. Spell hook doesn't leak as you said, and others too. But i might be wrong, so if you're no sure where it leaks please tell me exactly where it does.
Good luck with the project!!!