the Bitcoin system could ever be frozen due to non-activity or a community consensus - could the blockchain be frozen?
The volume of transaction is on the uptrend as bitcoin's adoption rate is increasing. How could be non-activity. The community would never allow freeze the bitcoin system, and it wouldn't happen at the moment or the near future.
What if the miners decided to stop working? What if the community decided to stop validating transactions? Wouldn't that freeze the blockchain and thereby put a halt to bitcoin the currency?
As long as bitcoin has value in terms of fiat money, miners wouldn't decide to stop working, at least for most of them.