minor factions as long-term partners

Introduction

The minor factions are a nice feature in the early game. But they lack a long-term use and vanish pretty fast, which is sad condsiderin how much love the devs probably put into creating them.

With the Hisho-dlc the pirates are even deeper in diplomatic engagements than the minor (civilized) factions.

Even worse: The current assimilation feature is frustrating/infuriating in times. 

Problem

I had in several games minor factions as friends that were maybe even next to my systems and needed their manpower, the option to buy ships or other features they provide. 

Then suddenly another major faction from the other side of the galaxy found them, gave them some spare influence points to comfort them and boom, assimalted them. 

They now have a System next to me without any way for me to see it coming or even preventing it. In addition I lose my partner and maybe the needed ressource (e.g. manpower).

Neither do I see the assimilation comming nor can I prevent it. Even if I had the maximum possible influence on them and they really love me: another faction can come, gain enaugh favour to barely assimilate them and they get my verry best friend as a slave to their reign.

Even when I take the time to bring my ships over to that system and siege it (after gathering enaugh manpower to invade it which is actually a problem for I don't get the manpower they did provide), I can only take the system for myself or destroy it. I cannot revive the minor faction.

And to top it all: I have to declare war on that faction from the other side of the galaxy to get rid of their infiltration and take the diplomatic blame for it (if I can even pay for the declaration of war).

Two of my friends complained about the same issue to me, so I don't think I am the only one that finds that to be annoying.

Ideas

I played maaany hours of Sid Meyers CIV V and therefore got some inspiration by their minor faction system (city states). Also I took an idea from Total War Medieval II (pope-state)

general improvement:

- provide a way to protect the minor factions from enemy assimilation

- give me a way to see the assimilation comming

- make it possible to revive them -> they are verry gratefull thanks you in a fitting way

- give the option to offer a known minor faction refuge when they get conquered -> giving them a planet / system of yours -> they ofc are verry gratefull to you
- get strategic / luxury ressources from their planet / system
- get the bonus of the galaxy branch when you controll all systems but the ones with the minor faction and they are your friends

two bigger changes (more of a wild idea; both not depending on each other):

- make it possible to settle in their system with them still controlling their planet (would affect the last three ideas above, so they would need some tweaking)

- give an option to make them a vassal/liege -> keep their independence but are working for only you as long as they arent conquered

possible ways of interactions:

- give them ships / manpower / dust
- ask them to help in a certain war

- ask them to scout a part of the galaxy

- ask them to let a certain faction not pass their territory

- get regularely quests from them
-> tasks: giving ressources, scouting something, defeating a pirate ship / base, declaring war on someone, etc.
-> rewards: experience, ressources, a boost on happiness, political influence in your parlament, information on other factions, thinks your would find in curiosities like special techs or battle plans , etc.