On his own, the coolest robot ever. With his trusty sidekick, "Threepio", he becomes the 2nd member of the duo known as "Ugh, Those Two Again".
R2 is a tube with wheels. He should be able to perform the following functions under regular conditions:
1) Go forward - wheels and simple control should allow him to move towards something he wants to be closer to
2) Go backward - wheels and simple control should allow him to move away from something he wants to be farther away from
3) Spin on the spot - wheels and simple control should allow him to spin, for any number of reasons (yet another Star Wars dance sequence, anyone?)
R2 is a tube with wheels. He should not be able to ably perform the following functions under any conditions:
1) Fly - apparently, in the olden days, R2 had jet packs in his shoulders. Where else? It makes sense that he would get rid of these at some point as to be more useless as time goes on.
2) Fly a Starfighter - I can buy if he can start the engine, kill the engine and maybe hover but this dude has one eye and barely even understands that he exists.
3) Keep things to himself - Luke "Skywalker", you say? Huh, I knew a dude some time ago with that family name. Probably not important. Continue cleaning my diodes.
Most of R2's bleep's and bloop's were most likely him saying shit like "Yeah, yeah, I know who Obi-Wan is, don't worry about it..." and "Shut up Threepio, you don't know what the fuck you're talking about!". See, R2 knows what happened in the first three films and didn't have his memory wiped to cover Lucas' ass like Threepio did.
"How. The. FUCK did I get here?"
When Leia puts Death Star plan inside him, he bleeps "Oh this thing again. I heard about this 25 years ago...did you guys want a head's up??"
Couldn't R2 have filled Threepio in a little bit while they were escape podding (it's a new sport) down to Tattooine? Did they just play "I Spy" or "Guess the Form of Communication" the whole way down?
We think R2 gets a little too much "Yeah, you my droid, dog" and not enough "Hey, asshole, be a team player!"