If you know the names of them, your answers are waiting: just go to Clematis on the Web and do an A-Z search. If not, then COTW will still be able to guide you. My little search just came up with the fact that you're entirely correct about the way you treat Blue Bird, also that BB can be planted anywhere. C. Viticella itself is a Group 3 and yes, just cut it back to about a couple of feet in the spring. There are quite a few other viticellas; just go to the Clematis A-Z button and click the letter you want, and it'll have a list of every clematis that exists (well, only if you have the correct name!).
Good luck!
Oh! Here's the COTW website -
http://www.clematis.hull.ac.uk...
