I haven't had time to go over the 100+ pages on the topic
And it shows.
sideZerocoins are not convertible to scZerocoins and therefore BTC. They are it's own unique asset and therfore not inflationary to BTC
As far as your second point about a fixed supply of 21M BTC always holding value despite being spread out over a thousand different sidechains? Think if it this way. You're taking a chunk of highly valued, highly secure coins off an unhackable ledger and moving them over to a thousand different insecure quite hackable ledgers. The equilibrium BTC price after arb will be dragged lower