Is R2D2 a good fighter or not?

Star5wars4kid

R2D2 is a good character to have on your team for stealth or even just to fight. R2D2 is my favourite droid

Autumn

If you have GL Leia you can use him there... otherwise he is useful with CLS if you don't have threepio and chewie

Zumwan

Assuming OP is relatively new to the game, I don't think they'll have GL Leia.
R2 can be useful in a variety of comps early game: Commander Luke Skywalker, Resistance with Rey Jedi Training, even Galactic Republic with Padme. It is with GL Leia where it really shines, but you'll find some uses.