I am a German citizen with a US green card, currently living and working in SF. For family reasons, I will have to move back to Germany for a little while. Does anyone have experience with how I would handle my taxes? Would I be in danger of losing my green card status in the US? Who would be a good source to contact?
As a US green card holder, you may not stay for more than 1 year without requesting a re-entry permit.
Regarding taxes, as a green card holder, you will also be subject to US taxes even if living in Germany. But, if continuing to work for a US company remotely, and paid in the US, this will not be a problem, and can actually be a benefit if you will remain at least 330 days.
If at least 330 days, you can claim deductions of foreign earned income exclusion (basically $100k tax free, plus housing and other deductions).
TL;DR - if you stay 330 days in Germany, there are strong tax advantages. If you stay more than 364 days, you could lose your green card.