You've answered your own question, then. The staff has nothing to do with the pen, and yes RP's with options get moved down and back when teams are taxed if the rotation takes a hit. 6 RP's are unfathomable, it worked in the 70's and 80's, not anymore. The bench will be a strong 4, maybe not early in April as the schedule is lax, but...
P.S. SP's innings from last year have no bearing moving forward.