There is no philosophy in Bitcoin. It is not anarchic, libertarian, Austrian or anonymous. It is just an internet protocol and a bunch of people that use it to transact between each other.
The protocol has purely technical and monetary measures to prevent spam, DoS, double spending and reversal of transactions. Transactions themselves do not advertise their purpose or identities of people involved.
It is not “against Bitcoin spirit” to have non-anonymous service built on top of Bitcoin. It is not a “hack” to use Bitcoin addresses generated not from random numbers, but from document hashes to implement secure document timestamping.
You can do whatever you want with Bitcoin as long as your transactions are compliant with the protocol and you pay the fees when needed. You can use it as a currency. Or as a payment system. Or as an investment. Or not use any of its monetary properties whatsoever, but use it to register predictions about the future. You can use it in clear to accept donations for a good cause, or you can use it through Tor network to buy illegal stuff. You may require others to identify themselves before accepting payments, or you may allow your customers to hide their identities from you. After all, you can avoid the whole thing completely and live a happy life.
If there is a single philosophical thing about Bitcoin, it is this one: voluntarism. On the internet, across oceans and thousands of walls, you cannot force another person to do what you want. And neither can he or she. Therefore, to make a deal with another person, you have to negotiate and find consensus. And if you envision risks and potential problems, you are free to creatively find voluntary solutions to them, which will also be part of negotiation. No amount of unilateral declarations, laws or appeals to objectivist philosophy will make another person send you bitcoins. Only negotiation and reasoning give you a chance to get what you want.