You do not need new bolts but you do need thread sealer (note: not thread LOCK) but I cant remember which brand/strength. I would go with GM aluminum LIM gaskets from any chevy dealer. Mine were $66. I got my coolant elbows at the dealer. Some argue that the $4 ones from auto-zoo are fine, but I have read stories of those leaking right out of the box. Like I said I got my elbows at the dealer since I was already there for my LIM gaskets. Peace of mind.
For the valve cover gaskets, valve cover grommets and UIM gasket set I used fel-pro brand. Get high temp RTV for the corner of the valleys. The video will show you where to use it.
If the water pump is not leaking, I would leave it. Its not hard to get to if it goes.
As for the thermostat, sounds like its opening too soon. Mine was doing the same. A duralast 195* is what you should replace it with.
