Some people argue that something cannot ever be considered as money if you cannot get credit through it, so for example you want to buy real estate and you need a loan, this needs government approval. How can Bitcoin ever reach that point of acceptance by a government if ultimately Bitcoin is disruptive against all states and governments? Or can Bitcoin be money even if it can only be used as a gold substitute?
I don't think that what you're saying is in fact truth at all. Being considered as money has nothing to do with gaining credit, there is absolutely no link whatsoever. By that logic when a friend lends you some sugar because you are out of sugar and you'll buy him some more next week, then sugar is a 'money'.
You do not need government approval to get a loan, the bank or some private individual signs this off, of course they must comply with government regulation but they do not need approval from the government.
How is bitcoin disruptive to states and governments? Your point here is irrelevant anyways as my above point explains.
Bitcoin can be money, in fact you could argue it already is, the most basic of defintions are along the lines of 'something that can be used as a medium for exchange of goods and services' one could argue bitcoin already fits this definition.
Bitcoin is not a gold substitute and never will be, they are entirely different things. There are of course similarities in that they are both scarce and finite. Otherwise they function very differently, bitcoin being digital and gold being physical are the most obvious of things. Bitcoin has steps to overcome to be accepted as a payment method but it is entirely possible this could happen, with gold it will not happen, it is too bulky to be used.