Grav!ty
ShyGuyBri86
Aliens... I don't think Gundam had anything close to extra-terrestial life (I think Stargazer hinted some things about alien life).
Seed had a huge bit about alien life outside the solar system. George Glenn discovered Evidence 01 (Winged Whale) during his space voyage. I think Astray S may go into that further. (Delta Astray already gave us Martians, which unfortunately are just Human colonist...)
As for the person saying multi body-part gundam...
What, the RX-78-2, Victory and Impulse weren't ENOUGH for you?