Fist question: I don't know of a site where you can see all the pricing after a promo. I recommend chatting with a U-verse rep, they will be able to answer those questions. You can go here and a Chat link is on the right.
Second: When paying a bill, your payment will apply to the entire balance, there is no way to specify which part you're paying (I assume you mean Internet/TV/Phone). You bills will actually have a breakdowns of services and prices, so you'll be able to see how much each service is billed for.
Third. No, only one U-verse account is allowed at on address.
Did a post have a solution that worked for you? Help other people find solutions faster by marking posts that helped you as an "Accepted Solution". Learn about accepted solutions: Learn More.
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.