How can us use the TGE for wholy new game development.

#1 Your question is too broad. I have no idea how to focus it except in extreme generalities.

1. Design your game.
This is how you know what your target audience will experience. It gives you focus in design and prototyping.

2. Know the source.
If you need a God View camera with a specific field of view, you'll know it. And utilizing the Advanced Camera resource combined with information from the Orthographic Projection threads, you'll be able to do it. Or you could make a platformer, first-person game, or distinctive camera (ala Resident Evil).

3. ????
Your question is so vague that I have trouble even giving you a hint. I'd have the same question if you said "I know , how can I make a cool game?"

#2 1) Learn to post in the right forums.
2) Read through the source code for the Scripts and the Engine (C++)
3) Read resources and other forum posts
4) Read Torque documentation
5) Practice & prototype
6) Goto 2