High-strength thin-wall large diameter steel is not necessarily a recipe for dent resistance. In a private conversation, Georgena Terry warned me off of buying a FastWoman (several years back) for my wife. With the thin tubesets she then used, she was seeing more frequent occurrence of beer-canning with those frames. Still a great racing frame for her team, however, just don't dent it or squeeze it. We aren't that careful.
I really wonder what failure modes the OP needs to prevent, if it's not just ALL of them.