Sorry that no one replied to your post........I thought I would just let one of the more talented people do so, but here it goes.......
1. No
2. Check the resources thread.....discount trains online is my favorite.
3. Depends on what you are going to use it for.......I think, not sure, a ratio of 1/100 is good, but I haven't a clue.
4. Peter at TTTT-parts makes them.......there is also some talk of Overalnder eventually offering some TTTT parts but for right now you can buy them from Peter.