I'll be the first to admit that I know next to nothing about roses, except that they're pretty, they smell good and I like them. So perhaps for those who are knowledgeable, it's inherent in the type of rose as to whether or not any given rose has few to no thorns, is relatively prickly, or is so laden with thorns as to require chain mail to approach (why, yes, I did make the mistake of planting a Polareis in a spot that requires a bit of grooming. Which does not happen for reasons obvious to anyone familiar with that rose. )
Would it be redundant to add a field to the roses database to indicate that a particular rose is "heavily thorned," as opposed to just "thorned" or "thornless or almost thornless?"

I think that might be a largely subjective matter. For one thing, it's hard to judge the thorniness of a rose grown under different conditions or even under seemingly similar conditions. I think New Dawn is horribly thorny, for instance, but Henhouse, who also grows roses in Northern California, doesn't have any problem with that rose's thorns.

It would also be labor-intensive. The data have already been filled in for more than 6,000 roses. Would you be interested in looking up all of those roses and editing all of those entries to reflect the degree of thorniness?

I think the "heavily thorned" issue is best dealt with in plant comments, which are presented as personal opinions.

We probably need an article on rose thorns and the particular classes of roses that are heavily thorned or relatively thorn-free. I'll find out whether anyone in the Rose Forum wants to write an article of that type.