I have a decentralized social network problem. If the legal framework forces you to follow certain political issues. The project you need to be transparent about the team. So which country's legislation is best for this,
I think that you can go to the country that is used by exchange sites as their main quarter. Transparency is really important in crypto since it's all about money. So many scam projects make people are paying more attention to the transparency by the team.
or do all decentralized projects need to be anonymous?
Being anonymous or not become your own choice. You will be determining whether you must become anon or not but again people are always seeing a project with anonymous project as a scam project. If your project will be marked as a scam project and then you must not be surprised to see that. It's caused by people are seeing your project as an anon project.