Work for the foreign firm or how to make the relationship with the freelancer?

Good evening! Just say it's not about me, to resolve this issue should be resolved as part of my work. I hope to help people who have experienced this.

I understand that this is not a forum of lawyers (by the way there was no answer), but I hope here to meet people who have experienced this. And according to my observations this issue starts to be interested in the part of freelancers in certain moments of life.

This

— There is individual. The citizen of the Russian Federation. A regular freelancer.
— There is a customer development/site. A legal entity in Germany.
— From an account in Germany to a physical person sent weekly small sum from 400 to 600 euros per hours of development. The money goes to the account Rayffazenbank open to a natural person.

Required

To legitimize those relationships to the IRS, the service of exchange control and the Bank was satisfied.

Desirable:
— Pay less taxes.
— Spend less time on design.

Possible options

1. To conclude an employment contract between the entities.
2. Register IP the freelancer, and then to conclude the contract on provision of services between entrepreneur and legal entity.
3. A contract between a natural person (a freelancer) and a legal entity (firm) for the provision of paid services, like a contract.
4. To conclude the contract on transfer of non-exclusive copyright intellectual property rights (FOR) and to royaliti.
5. To do nothing, to continue to send and receive money.

So, what to do?