I'm learning C

#1 C++. Most of the code from what I can tell is based very closely on C++. The scripting is close too as well.

#2 You don't need to know C++ to use TGE. The scripts are powerful and simple enough to get most of what you need done. It uses a C like syntax but is really simple to learn.

C/C++ to do actual engine changes will be required. Just rent a good book or two from the library to get you started.

#3 I think the preferred nomenclature is "borrow", actually.

#4 Thanks, I dont think I will need to change the engine