1. I was using a 7290 before so I am familiar with most functions of BB, however I can not find an option on this one to control the backlight. I would like to have it how it was on my 7290 where the light only was on when I needed it to preserve battery life. Is there a way to do this?
The 7100 is different. It is an active matrix screen, so it is always on and always brighter. You can control the brightness by going into the Screen/Keyboard setting uders the options menu and changing the Backlight Brightness and Backlight Timeout.
2. Has anyone figured out how to alter the menu on the "homepage" I would prefer it look like the homepage on the 7290 with the icons all shown, and not having to go to applications and then other programs.
You are out of luck on this one. The menu structure in not modifiable. However, at the top of the "General Charm Discussion" section there is a sticky entitled "Noob guide to installing new Themes on 7100 series" which should help. Follow the instructions for installing the 7730 small icon theme. It works.
3. I had heard that this phone would come with an instant messanger program on it. I can not find this??? Anyone know if I am just missing it, or if there is one.
The T-Mobile 7100t comes with their built in IM client. You will need to purchase Verichat or some other third party IM client for the 7100g.
4. Also this is probably a long question to answer, but should web browsing be better on this phone then my old one?
No, it should be the same. What makes you think it should be "better". Brighter, more vibrant screen, but web browsing on a BB is web browsing on a BB.