Yes there are a lot of factors that bitcoin really can't be considered for replacing fiat. Even the price is getting higher and higher nowadays still that is not going to matter because in the end the government is the one that will be followed and law makers are coming from the. But let's see one day we will be having paperless transactions.
bitcoins value will be derived from how many people use it. when the user base of bitcoin becomes large enough, its conversion price to fiat currency will naturally stabilize and we wont see any crazy price swings like we did in the past
There is not a single chance of that
At least, not until instant, ping-time payments become available, and Bitcoin turns into a sort of "bad" money ("bad" money here refers to Gresham's Law obviously), though even in that case it is not given, either. Till then Bitcoin will remain mostly a speculative asset, and such assets can calm down only at zero level. There is simply no mechanism in place that would justify Bitcoin use for anything other than speculation on a large scale. And this is not going to change until and unless Bitcoin paradigm changes (e.g. due to introduction of payment channels with fast and free transactions)