First off that wasnt Episode III, it was IV. Anyways the small black droid is called a Mouse droid. What it was used for is beyond me. Perhaps wookiepedia knows.
Secondly the space slug was scary. Nuff said'
Thirdly CP30 is gold...very gold.
ATAT's are awesome. But you have to look at what ships are attacking it. A snow speeder was pretty much a scout type ship. It wasnt designed to be used in full scale assults. I'll bet if the Rebs wanted to stand and fight till the end the X-Wings would've kicked their asses.
Lastly ewoks are stupid. I'm glad there are none in TOR.
Seriously though just dig around on wookiepedia.org on anything. Usually there is alotta good answer on their.
Cheers!