Few suggestions for some quick points and achievments.
Load up a bunch of points (AT-ST level has been previously mentioned) I liked using the level when the two clones are held hostage by Cad Bane and your closing the three doors. The challenge in the middle just before the end of the level is a peice of cake on its own for a quick 4500-5000 points. If you have invuneralbity and infinite ammo on mini gun you can wail a easy 6000-7000 in 45 sec.
You can buy all the items in a section (hats, upgrades whatnot) to unlock the achievement. Quickly end the mission from there and you lose all the upgrades and have all your points again. Buy another section and "another achievement"... dont know how useful this is because you need most of the upgrades for gold/plaitinum or dancing chievs... just thought it was cool.