As to the regular covers for some of the older roles seeming too young--that's not uncommon for the Weisslers. There have been many times in their shows where the have multiple cover tracks that they fill with people already in the ensemble but who they only want to put on in case of emergency. (Hence, Sabrina Harper being a cover for Berthe and going on when Martin or Feldshuh called out, but not during longer planned absences). Since Mann has had several instances during his run where he's gone to WCU to fulfill teaching obligations, they seem to have kept Sieber on hold to fill in as needed.
Back in the GREASE days, when Marcia Lewis wanted to take time off to do CHICAGO at Encores, the Weisslers initially refused because her understudy was a young chorus member. Lewis persuaded Dodie Goodman to come in and do two weeks, and the Weisslers agreed to let her take the time off then. It seems like that was a precedent that's been followed in Pippin.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body
