hello and welcome!
Well, let me say the 2 lenses you have aren't worth very much. I can guarantee they won't work on Canon but not sure about Nikon. In any case, they're not very good lenses so I wouldn't make a decision based upon them.
To answer some of your questions:
1. I don't think the live view is worth very much. It works well for certain types of shooting - macro, product etc where you want critical sharpness and have the time to get it. For general shooting it's not very useful. And without the use of a tripod, trying to hold a DSLR like a point-and-shoot and use the LCD will yield poorer results than holding it up to your face. The reason being a DSLR is heavier and holding it away from your body is a less stable shooting position. I wouldn't worry about it one bit.
2. No, the nikon is not too advanced. It has an auto mode.
I suggest you go to a store and handle both cameras - make sure you like the ergonomics. They're a bit different than one another so one may appeal to you more. Otherwise either one is a fine camera and will suit your general purpose shooting needs. The extra MP of the canon are really negligible.
When you decide on one here is what I would suggest:
Buy the camera with kit lens
Buy an external flash
Buy a 50mm 1.8 lens (<$100 in each system)
You're going to want shots that will require a flash and an external bouncable flash will improve your flash shots 10-fold. The 50mm 1.8 will allow you to take some available light shots indoors and some shallow-DOF portrait shots which are one of the true benefits of a DSLR over a point-and-shoot.