One of the cool things about a sandbox is that you don't really need to roleplay, because you're not just following rules nor a strict path, you just do what you feel like doing and the game reacts to it, so by just playing, you're already roleplaying.
Obviously the game isn't fleshed out enough for some interesting sandbox-powered roleplaying, but it's only going to get better.
Good point. I wouldn't consider myself as a roleplayer by any stretch (I like CRPGs and even did some AD&D pen and paper ~25 years back, but that hardly makes me a roleplayer).
If I'm wearing my rift and I'm in a spaceship, I'm still me and I certainly won't start saying things like "Salve Amicus Imperii!" trying to ape an asian sounding accent on voice comms or anything like that (although the idea just made me giggle - I may do just that to irritate people, should I ever find out if ED voicecomms work
However, I prefer to have some background character in mind to fit into the 34th century (obviously my real life background doesn't fit). To spice things up, I losely based him on mainstream sci-fi cliches and watching the Black Adder for "interesting" moral implications.