I think it would be nothing not ordinary, so just one of their currencies would be more and bigger than bitcoin but it would not change that bitcoin is number one because it is not all about coinmarketcap.
Exactly. No problem. The market has only risen when new currencies appear, making demand for investors more involved.
There are many denominations higher than the BTC but it is not as popular as the BTC
Bitcoin will stay stable for a long time.