And to answer your questions
1. What breaks the most when bashing a Savage X 4.6 RTR.
-Generally the shocks will, however they are a really easy and cheap item to find on Ebay and won't let you down. The differentials are sloppy and the fuel tank will explode every time you decide to run without a body on and flip it.
2. What breaks the most when bashing a tmaxx 3.3
-The bulkheads and hinge pins, bad design, hinge pins will bend so bad you can barely get them out when you break the bulk heads. Also, it has plastic drive shafts instead of CVD's like the Losi rigs or Savage
3. Will a Savage X 4.6 RTR survive my idea of fun above?
-The Savage will easily survive what your talking about. You can do that plus more and have a good time without worry.
4. Is my ofna box starter worthless? No bump start on MT?
-Most MT's will not take a Bump box because of how the engine is located and mounted, it's not worthless, but no good for a MT
5. What temp gun should I get?
-I use a Orion one but Duratrax has a good one as well
6. Do I really need to change the servo's to have fun?
-No, however, stock servos are weak and underpowered, and if your going to bash a lot you'll need to replace the steering servo with something that has over 180 oz of torque.
7. Tmaxx 3.3 or Savage X 4.6 for my needs?
-Losi Aftershock or XXL
Or
Savage X
Stay away from the Tmaxx unless you like buying and fixing it, every tank.