Stryker i realy like your idea ,
having magic infested terrans makes is possible to exceed supply balance .
in the campaign infestors could infest ANY unit , a spell that id say is 2x as effective as snipe but takes the same role , as that it is best used agenst Large units and not small .
while i feel that such accents make zerg more zerg like , in order to bring it back in id like to see toss get mind control back , as they would essentially be the same spell , just different lore . terran would get the short end of the stick on this one as the 2/3 asymmetrical balance is essential to the feel of StarCraft