In short, highly unlikely, specially for a fermi GPU. I would personally go for @ least a 360, even better 360 and 240 should be a good amount to keep both very cool. & yes, thermal adhesive is gross... You may be able to find double sided thermal tape? May want to go over to "The Mod" club for better advice.
True, though if you read the directions supplied by most waterblock manufacturer's they recommend using both. A dot of TIM directly on the vrm/vram & thermal pad on top.
Is this the best setup?