I personally would go with a Rose of Sharron or a dwarf crape myrtle. Both are easy to grow and would give you great color all summer long. I have actually never grown or seen a Robin Hood Rose so I cant answer your question about the thorns.

http://springhillnursery.com/rose-of-sharon-hedge/p/80208/

or

http://springhillnursery.com/search.asp?ss=crape+murtle&x=0amp;y=0

~ Danni Girl

I grew Robin Hood rose for several years. It grew about 4 feet tall and wide in some shade. It only bloomed one large flush of blooms in spring and a few in fall. About average thorns. It's a hybrid musk which will take some shade, but it might be larger in sun. If you really want a rose, Belinda's Dream is about 4 to 5 feet high and can get really wide if it's not cut back. It blooms all summer, but the blooms are light pink. I love roses and grow a lot, but they are a lot of work to keep them looking good in Okla. You might want to consider something else, unless you really like roses and don't mind their problems.