First, let me apologize for sending you the wrong info in reply to your email. I gave you info for the AV3100, missing the fact that you have a VL900, so I'm glad I asked you to post your questions in the forum.
Getting to video 7 is not easy with the VL900, but it can be done.
Check out
this thread, post #4.
I don't think you have a TV/Tuner button on the 900, so you will have to learn it. This will get you to a constant starting point. Then you need to make a macro using the TV/Tuner button plus the correct number of TV/Video commands to get to the desired input. Since you can only make 3 macros on the System Control buttons, you might have to use the Component Select buttons to make any additional macros you might need.
If your TV has the capability of skipping unused inputs, you could eliminate any that are not being used to shorten your macro.
For your second question, the RM-VL900 is a learning remote. Pick any unused key and learn what you don't have on it already.