Blockading Planets

I don't see you can't play a UN Peacekeeper... not 100% sure why you'd want to though.

You'd also be effectively restricting them from mounting a counterstrike. Unless its just a minor that won't concede, anyone else youre defending will probably cave in and give away their planets unless you're blockading multiple worlds.

I've done it before. Keeping all the minors alive makes for an interesting personal goal, especially since they like to declare war on each other. One time this got me into a WWI-type situation as the near-defeated race I defended them from turned out to have a lot of allies.

Cool.

Yeah, I like forming a federation of minors. Among other things, it give you a good excuse to go to war against bullying majors without feeling like a total warmonger.

I mostly like forming a federation of minors because if they're close or friendly with me (much less Allies), they tend to send their trade ships to my empire. I then give them trading techs, and often time, the starbases and freighters needed to maintain trade routes to my more economically prosperous systems.

One time I had the Yor as a major race, and the Dark Yor as a minor. Just for fun, I used diplomacy and conquest to take all of the Yor's empire, and give it over to the Dark Yor. I also gave them combat vessels (since minors don't seem to make use of them). The Dark Yor was stronger militarily and economically than some of the major races when I was done with them.

I've tried, but the enemy just smashes straight through before you can fight back, not a good idea.

I guess being able to make a "Defense Pact" with minors should be added to the wishlist?