How to fix a bent alloy rim at home?

Aluminum has a low melting temp. But it dissipates heat quickly. If you heat it slowly and only heat it enough to soften it you should be ok. Do not quench it. Just heat it lightly and hammer it using a strait edge to track your progress. You have to heat metal quite a bit for it to get brittle, like red hot. Quenching makes it more brittle.