I would, at least temporarily,freeze/turn off JUICE DEFENDER.Reason is you are already using ANDROID ASSISTANT,&together with the stock O/S,you've got 3 different things telling the phone what to do.You're probably using more battery than you're actually saving w/this set-up.
I would suggest reading some recent threads/posts on JUICE DEFENDER to get a well rounded idea what this app actually does.
Also,w/ANDROID ASSISTANT,I would only use that to kill tasks that have no other direct effect on any other apps,a stand alone app.,if you will.Reason for that is the stock O/S is just going to try to turn that app back on again,consuming more battery & causing lag by constantly having apps turning on & off.
It doesn't sound like you have too many apps on your phone,you have plenty of memory left for this to be an issue.
If you have TITANIUM BACKUP PRO,I would suggest freezing any apps that you don't use that you are sure will not interfere with other app functions.If you don't have TB PRO,I believe there are apps available to freeze un-needed apps.The 1st I would freeze is CANVAS,&then proceed from there.
I know almost all of us have WIDGETS that we like to use.I have read that having too many will definitely cause lag.What that magic number is,I don't know,wish that I did.Hopefully you won't have to resort to eliminating WIDGETS to get better performance,that would kinda defeat the purpose of having a smart phone to begin with.
Last but not least,if you can't get better performance no matter what you try,you may want to consider installing the ICARUS 1.1 MOD.The performance of this MOD reportedly blows away the stock 2.1 ECLAIR O/S.