Yes. While we know relatively little about the atmospheres of individual expolanets, there is no reason an exoplanet couldn't have an exosphere.
which exoplanet is 'THE exoplanet'?
The darkest exoplanet is "TRES-2B".
No. An exoplanet is a planet outside of our Solar System.
51 Pegasi itself isn't an exoplanet, it's a Sun-like Star. But it does have an Exoplanet orbiting it, 51 Pegasi b (informally named Bellerophon.).
No. A moon is not a planet. An exoplanet is aplanet that orbits a star other than the sun.
Both exoplanet and extrasolar planet are planets that are outside the solar sysytem.
The exosphere is rainbow
No. The nearest exoplanet is more than four light years. We cannot travel anywhere close to that distance
The exosphere's job is to hold satellites
what is the thickness of the exosphere
Exosphere
We do not know enough about conditions on any exoplanet to determine if any would be suitable for humans.