Do I need an endorsement from a Buddhist or Taoist association to run a Buddhist website?

Look at the scale, not necessarily small. This kind of thing is ignored by the public without telling officials, which is a great need. But you'd better check the relevant laws. As for Buddhism and Taoism, it is the counterpart unit used by the official religious administrative department to restrict and legalize folk beliefs. It has no actual rights, and the final decision can only be made in the religious office of the local government.