I actually had a similar requirement, but the best I could get was adding the T&C on the last page.
If you have PAGE1 with your main form and PAGE2 with your T&C and set PAGE1 next page to PAGE2 you will not get PAGE2 on a one page document. You have to add a command to call the PAGE2 with your T&C in the MAIN of PAGE1.
But also for a multiple paged document you cannot set the PAGE1 next page to PAGE2 because the page numbers get messed up and it actually ends up printing all your PAGE1 pages on top of each other with a "Page 1 of 1" displayed. Even if you try to make a page loop where PAGE1 has next page PAGE2 and PAGE2 has next page PAGE1 it does the same thing. So for multiple paged doc you have to set the next page of PAGE1 to PAGE1.
The end result is PAGE1 has a next page of PAGE1, and a command is at the end of the MAIN in PAGE1 to call PAGE2. The PAGE1 will have Print mode as blank and PAGE2 will be set to D for duplex. Also for my T&C page there is no page count so to not have this page taken into account you need to set in the General Attributes where "Page and Overall Page Unchanged".