RTV is simply a kind of silicone in a tube. It just means room temperature vulcanizing & all auto parts stores have it.
it could mean quite a few things, but blown head gasket is one.
you mean a valve cover gasket i think
you mean like k seal?, there only temp fix if that, the gasket should always be replaced if its failed
Blown head gasket.
A blown head or gasket
blow a gasket, blow a fuse : pushed past some tolerance level into an angry fit.
If you're referring to the water pump gasket, and, if you're changing a faulty water pump, a gasket should come with it and also needs to be changed (Use the grey Permatex gasket sealant on the new gasket). If you're referring to the head gasket - not necessarily.
Assuming you mean "valve cover gasket", the gasket seals the valve cover to the head so as not to leak oil.
you probably have a blown head gasket
blown head gasket
Probably a blown head gasket
Not sure what you mean but I'm thinking "gasket".