source code

#1 Have you tried building your game with the demo?
Did you run into limitations with TorqeScript that requires some more advanced techniques?
Do you understand the coding language the source code is written in? (I currently don't remember which it is)
Do you need to modify the binary for whatever reason?

There is quite the number of questions you should know the answer to when licensing. The answers to these and other such questions will help you determine if you need to license the source code.

#2 how I check the source code if I can understand it and modify it or not ?

#3 Word with the demo first see if your concepts can be made using scripting alone.

The source code is all in C++, so you will have to know it to modify the engine.

#4 thanks, I know C++ well but I dont know if it is possible to conclude 3D equations and functions it is hard for me I think and I am afraid to stuck in the middle.