I have started to change the head gasket on my 1995 Honda Civic EX and have run into three problems, so far.

1. One bolt is stuck on the exhaust manifold heat shield - rusted, frozen, rounded the head.
2. One bolt on the timing belt cover is so tight it is in the cover slot for the bolt and I can't get a socket or wrench on it.
3. Nut on the backside of the engine holding the intake manifold is too hard to access and the extension interferes with the manifold.

How do I remove these??

Another question - does the engine have to be at TDC prior to head removal for proper timing and if so, how is that done?