BIP42 is a fix to an accidental bug that made the money supply larger than anticipated. I think it is pretty clear that Satoshi did intend to make the money supply capped at 21 million right from the start.
I agree, but IMO with BIP 42, we confidently can say that 21 million coin supply is part of Bitcoin principle and prevent troll/FUD by showing buggy code.
Less Difficulty = Less Miner = Less Secure
Fair point, but there are many factors besides mining reward and total fees on a block :
1. Bitcoin price (higher)
2. ASIC efficiency (more efficient/faster)
3. Cheaper price (cheaper)
4. Transaction count (more transaction count)
5. Transaction fees (higher transaction fees)
If some of mentioned possibility happen, bitcoin network wouldn't be less secure in distant future
BTW At That Time, Maybe People Will Switch To Another Blockchain/Payment Method
It's possible