The only other crypto currency I can think of replacing the bitcoin is the Ethereum. Many bitcoiners are buying it.
I think so. The Ethereum trading volume is even higher than the bitcoin at the moment. So people are interested in it.
Yes ethereum is doing a good job now but still it is below bitcoin and really far. A lot are supporting ETH yes but with popularity and usage now it is still bitcoin who have the most. Maybe someday it will change.