Are the base stations/index 240 or 110 volts

I think they are 12v maybe less, with a wall wart. The difference between v1 and v2 is v1 has 2 spinning motors requiring more wattage. V1 wart will power V2 but not the other way around. As for 240 or 110, the plug will be different on the ac adapter

All three power supplies that come with the Index kit work for 120/240 (+/- the usual voltage allowance for electronics) at the wall. The actual devices use 12v, and can be powered by any power supply that meets the output specs of the devices.

For the official supplies the only thing that needs to be swapped out is the actual plug, which works much like the Steam Link's power supply. If you're in the EU you will receive the appropriate plug already. If you're in the US you will get the US plugs. If you're ordering in an unsupported country through a third party, you'll get whatever plug they would get in their location, and you'll have to find something that works for you.

yes