Yep, it seems in all situations no 100% legal option exist.
If i will work only 100% remote jobs I will in competition with all the other persons who bill cheapers.
My only way to bill good rates is to show my face in the offices in Germany. Then i need to figure out hiw to pay less taxes.
It seems playing with opening new companies under my name will trigger the control for sure.
I start thinking to use a nominee to open a company under his name and build email exchanges beween us showing that I delegate the job to him. For example if I bill my client 600eur a day I pay my subcontractor 400 a day,︀ then i live and spend the money of the subcontractors and keep my company money︁ saved for the future.
As my actual turnover is not huge money I think that︂ is the only way to save taxes.