There are certain "believability minimums" you run into when dealing with interstellar-capable civs since these have to be K2 civilizations with access to fusion energy as a minimum. Any less and its patently unbelievable that they're capable of interstellar travel. Coming off the whole mention of "hypergates" (which you mention in passing and then don't proceed to set FTL limits) suddenly you could be dealing with civilizations that haven't gone interstellar of their own means, but any such civilization would very much not be prepared for first contact with another spacefaring race far away.

Just some random thoughts having done my share of sci-fi worldbuilding.