No, they are mostly red dwarf stars.
No, red giant stars are not the largest stars in the universe. There are stars known as supergiant and hypergiant stars that are even larger than red giants. These stars can be hundreds to thousands of times larger than our Sun.
The Milky Way galaxy contains mostly older stars with a red color, particularly in the central bulge and halo regions. These stars are typically red giants and red dwarfs, which have aged and evolved from their initial blue color to appear red as they reach the end of their life cycles.
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.
Yes, there are. The classic red giants that come from sun- like stars, and red supergiants come from blue 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.
With red giants and main sequence stars they are not entirely featureless, therefore there is no name for them.
Red giants, red supergiants.
White Dwarfs, Supergiants, and Red Giants are stars that are found in the sky.
Red Giants. Stars not on the main sequence