To clarify the role of comm buoys and sniffers
By default, missions are posted not by factions generally but the governing authority of specific colonies, and you only hear about missions posted by colonies that you are close to. A comm sniffer will allow you to discover missions posted in that system from any relay. A single sniffer will never be detected, multiple sniffers leads to a risk that one will be removed at random. When that happened I didn't notice a reputation hit, but it's possible that comm was under pirate raider control when it was caught.
In my current save I put a sniffer on one of the two worlds with a Luddic Path colony and used the exploration missions to get non-hostile with the Path, and then built colonies in a system with two nice prospects and a Pather base. The Pather fleets guarding that base kill Hegemony AI inspections and most expeditions for me. (The Luddic Church doesn't like my free port and I have to deal with those myself.)
(Note: in fact I was not totally out of hostilities with the path when I first established a colony, and that made a lot of problems for me because it drove me to start on the high hazard class 4 instead of the 125% that their base is orbiting. But now that things are established the Pathers are well worth the trade disruptions they occasionally cause.)