i played with mobile data a lot too, if you just want to pve you can even play with an edge connection, but in pvp combat it can get a lil problematic.
and for the data, an hour of hub idling consumes around 4 million bytes, which is like 4mbs, so you don't really need to care about data consuming rate. you can check the data consumed anytime at the f1 info screen as well.