Do not apply the tape to gas compression accessories, removable nuts and screws used to connect two gas tubes. Gas connections are at the end of the gas tubes and are not removable.

You should not need to use sealing on joints. Most exhaust gaskets come either with their own sealing (such as Fel-Pros do with silver look tricks), or they are made of metal and do not require it either. If you do not, you may have slight low spots in your collector that could allow exhaust leaks.

Some applications used an original RTV, but normally the new thermostat will have a fiber seal. With a 0 rubber seal ring, I wouldn't use the water seal naturally. For me, it depends on the water seal. If it's a quality boa seal, I don't normally use the water seal.

When you change a water pump, replace all the old and joints with new joints. If your new pump is equipped with a joint, make sure you are in impeccable condition before installing it. You may be tempted to apply a sealing joint on a ring or a dry joint, just to be safer, but these joints don't need a sealing joint!

I put a RTV coat on them. I never used sealant on paper seals. With flat surfaces and correct pair you shouldn't need it. With flat surfaces, smooth and correct torch you shouldn't need a seal.