Can payment from a P2SH address provide change to itself?
These two things are actually not related. There are no restrictions to address reuse in the protocol. You could get away with never using more than a single address ever (although that is not recommended especially for privacy reasons) and p2sh addresses are no exception there.

The redeem script encodes the conditions that have to be fulfilled in order to spend funds from an unspent transaction output (UTXO). What the sentence says, is that you cannot have a lock to another redeem script inside of a redeem script.