Here's a strange question, Will different wieght fluid in my rear diff help me as I am still learning to drive. The model is a sportwerks turmoil rtr mostly upgraded to the pro version. Wondering if I should go with a 2000 or 3000 fluid in the rear on a 5-7-? set up. thanks.

5-7-3 is a normal baseline setup. I would try that then go higher or lower.

5-7-3 is a average set up for all purpose driving. Changing diff set up depends on where you are running, and what track conditions are.

Go with 2k in the rear to help with steering.

IMO 3k for the rear is higher than average. Most pro setups use 2k or 1k.
Have a read of this.
http://users.pandora.be/elvo/

My turmoil was pretty hard to handle, It was always loose. I ended up using 10-7-3 it worked about the best on the track that I run. When I went to other tracks I had to change. I have 7 loose diffs with differnt oils in in them for quick changes.