Yes and yes

Thank you! Would be fun to pursue.

If you look at the lineages of all the major rose groups, it's obvious they have been repeatedly backcrossed (culminating in the Grandiflora group).

Another strategy would be going back and making the same cross with the original parents again, to see if something different results. Maybe there were some traits that were lost in the previous crossing.

Since every rose seed is a new variety doing the same cross repeatedly will always produce different results. Many breeders have repeated cross over the years and produced beautiful new varieties.