No, they are mostly red dwarf stars.
Yes red giants are the largest. But the bigger stars of red giants can be called red hyper giants.
The large hot stars are typically called "blue-white" stars or also Blue Giants. Cooler large stars are called Red Giants.
If they have red stars including giants in, they can't be all that featureless.
Most medium mass stars such as our Sun DO become red giants. Smaller stars do not have enough mass to initiate helium fusion when the hydrogen supply begins to run low, and do not become red giants.
All stars eventually turn into Red Giants or Super Giants
I think you are referring to red giants.
No, red giants are generally older than main sequence stars, as red giants have no hydrogen left for fuel, and burn helium instead. where as Main Sequence stars burn hydrogen for fuel.
Yes, there are. The classic red giants that come from sun- like stars, and red supergiants come from blue giants.
With red giants and main sequence stars they are not entirely featureless, therefore there is no name for them.
Red giants, red supergiants.
Red Giants. Stars not on the main sequence
White Dwarfs, Supergiants, and Red Giants are stars that are found in the sky.