Actually there is no Pokemon fully unaffected to fire types but there are some that are resistant like water, ground, and rock
just examples
There is a constant sandstorm on route 228 on Pokemon Diamond. It is not possible to ever remove this sandstorm.
No, it does not.
Regirock
No
no
You need to get the go-go goggles.
Steel. These Pokemon include: Empoleon, Steelix, Mawile, etc.
If you evolve it to gliscor, yes, especially for sandstorm and stall teams.
The Root fossil is the Pokemon Lileep and the Claw fossil is anorith =D
Dark-type pokemon are resistant to Dark and Ghost moves, and are unaffected by Psychic.
Catch after the National Dex on the route with the sandstorm or evolve Hippopotas
Well you can go to the place with the big sandstorm is and catch some Pokemon and battle some people