Can/should I use rapid rise yeast for longer proofing? More generally, what are the limitations of rapid rise yeast compared to other types of yeast?
Rapid rise yeast has enhancers added to make the yeast more active and lower the amount of time needed to proof the dough.

I wouldn't use it if I wanted a longer proofing time because I think the dough would rise too far wouldn't result in a good crumb or flavor.  That being said I think you could use rapid rise yeast with a longer proofing time.  Maybe you would want the larger volume of dough and other effects.