Hi, Tina. Here are a few quick answers to the questions that allow for quick answers:
Tree rose trunks do not grow taller. The only part of a tree rose that continues to grow is the top portion, which is grafted onto the trunk.
Rose bands are the small containers in which many own-root nurseries offer their products. They're less than half the size of a gallon container. I don't have any to measure, but I'd estimate that they're about 3 inches square at the top and 6 inches deep.
The roots on body-bag roses sometimes have been pruned so radically that they can't support the top growth. If a body-bag rose has inadequate roots, the canes of the rose must be pruned down, approximately to the same length as the roots.
I think CindiKS is writing an article about growing roses in containers. In any case, it's too complex a subject to cover in a few sentences.
The same is true of overwintering, and I'm not the person to ask anyway because I live in zone 9.
Thornless roses are a delight and are especially wonderful near children's play structures, near entryways, and along narrow pathways. Many roses are thornless or almost thornless. You can find a list of them if you go to the main page of the Roses Database and click on "Search by characteristics."
The Roses Database
On the search query page, scroll down about halfway to the "Misc" section, check the box for "Thornless or almost thornless," and click on "Search." You'll get a long list of roses. (I'd do this for you, but our search engine isn't sensitive enough to provide links to the results. My link would only take you to the blank search query page.)
Chain-mail gloves sound great, but I've never seen any. I wear Atlas Thermal gloves every day of the year, and they offer me enough protection. If I'm going to be pruning some roses with dense growth and nasty thorns, I wear gauntlet gloves to protect my arms.
