Don't let him charge you for YOUR time when he asks you, what the blazes is Bitcoin? and then you have to explain
You have no idea what you are talking about. No halfway competent or decent tax attorney will have any idea what he is talking about.
I don't know how you pay income taxes, what you need to file with the government, and who does this service for swedes, or how taxes are calculated in Sweden. I would find someone inside your country who knows a lot about your countries individual and business tax laws and consult with them. Pay THEM for their time. You can probably set up a low cost or possibly free initial consultation. If you were in the US you would be wise to set up a corporate structure and pay someone for good tax and business advice.