I have a Raz-r, same thing with a truggy body and truck wheels. Three of us have them. All of use use the 25c 5000mah 2s batteries. When we get together we do run them pretty hard. Never had an issue with the motors or ESC yet. We went through 5 of the 5000mah batteries and a couple of the 2300 batteries in a short time. Never did let them rest. Changed the batteries, handed the Tx to some one else and they ran it. The setups in this car are not going to pull enough to need a 50c battery. For giggles I ran mine with my 1300mah 50c battery. Nothing changed except run time.
When we changed the rims and tires to a new set of Gladiators, we did see a small rise in motor temps. The tires do not slip or slide, they grab like velcro.
You can get a watt meter that will not break the bank. Seems they are out of stock
http://www.hobbypartz.com/aeo-p0-watt-meter.html
Or here
http://www.hobbyking.com/hobbyking/s...eter_100A.html
http://www.hobbyking.com/hobbyking/s...Analyzer_.html
Sounds like you have it pretty much figured out.
Buzz.