Thanks!

The logic of "big ears and eyes are good in heavily forested environments" actually already comes into play with one of my races, the Zerdans. Despite being Space Fennecs, their homeworld is a heavily forested one, rather than the sort of desert-dominated world one would expect a race of fennec-like creatures to come from. I considered a very similar world would suit these Space Gazelles quite well, a world covered in dense forests, sprawling rainforests and jungles, thick mangroves, and the occasional grassland and prairie seems quite suitable.

It might also add to their mystique a bit if they're no longer threatened by the predators that once menaced them and forced this sort of evolutionary path, if any question about what happened to the aggressive carnivores that hunted them ever came up they might simply dismiss it with a vague statement like "it's no longer an issue" or "we outlived them" or "we resolved the problem in the past"--such a statement is vaguely threatening and would hint at a very real willingness to use violence under certain circumstances, and might explain why a group that seems like Space Hippies at first glance never runs into any conflict with factions that would appear to have the upper hand in regards to technological and military strength.

I guess at some point I do need to go more into various philosophies about "temporal prime directives" and "first contact" and other Star Trek-esque techobabble. I kinda see this Alliance of Free Planets (name subject to change, of course, as it's a very generic name) having a sort of "middle of the road" approach to making contact with new worlds, trying to be a bit more secretive about it and meeting with world leaders and coming to a conclusion as to how to proceed on a case-by-case basis. Some worlds might welcome alien visitors with open arms and become willing participants in an interstellar community, while other worlds might take a more reserved route, accepting a sort of "protectorate" status until the population as a whole is ready, and maybe have an organization similar to the Men In Black working in conjunction with the Alliance to keep the planet safe from other alien threats in the meantime.
Earth as we know it might actually be the perfect example of a world that's in a strange middle ground where it's not ready for "full participation", very primitive peoples would probably welcome visitors from the stars as deities, while more advanced worlds would likely recognize them as cosmic brethren, yet humanity exists in a strange middle state where we are still looking out into space to see who is out there, and sending messages for someone to answer, but overall not yet ready to answer whatever message aliens might send back.

In contrast, the two other oft-mentioned factions, the Lightbearer Dominion and the Cygnian Federation, represent more extreme ends of the spectrum--the Dominion often likes to make a show of their arrival and very openly make contact with as much of a world's population as they can all at once, regarding the concept of restricting contact and the terms of an interplanetary alliance to being solely through leaders in secret to be very undemocratic and an arrangement prone to abuse by "lesser" civilizations. Meanwhile, while the Cygnian Federation makes no effort to hide its existence, it's also not interested in expansion at all, and would likely only contact a world in close vicinity to them that somehow reached out first.