Should I hire a car or catch a bus? If I hire a car, do I need chains to get to the main visitor area?
The bus is certainly an easier option. You'd get the skybus from Melbourne Airport to Southern Cross and then get a Coach up to Hotham. Best to book in advance.
If you are looking to drive up, I think whether or not chains are required is very much dependent on the whether. I've only been to Falls Creek not Hotham but that was certainly the case with Falls. They were still recommended though. almost 10 years ago