1) i think that depends on the size/subspecialziation of the group you're joining. I've worked in two >100 rads PP's and the peds rads certainly took overnight fluoro call. But in both instances it was part of their total amount of call and/or they were paid for it. If you're joining a smaller group, there may not even dedicated peds call. And no, it was not mitigated by a dedicated night team. A lot of our dedicated night team work remote and are also too busy to go in to do a peds fluoro case anyway.
2) No, it's not particularly hard to get a job anywhere right now in radiology. Everywhere is short. If you're willing to read a lot outside your specialty, I'm pretty sure anyone would take you.
3) Just general considerations for peds in PP: you will likely read a lot outside your specialty. You will naturally have lower RVU's (less CT/MRI) and may be endlessly dealing with productivity discussions.