What happens to my invasion fleet after it successfully invades a planet? Does it randomly disappear? Or does it stay forever in that system for defense? Can I get them to follow me?
(Successful) invasion fleets, including ones sent by the player, will orbit the target for 90 days then go home. They won't obey the Follow Me command and can't be ordered around in general.
Seems like I encountered a problem, was commissioned by UAF during playthrough, then the faction got into an alliance w/ Iron shell & Hegemony. When browsing their market however I can't access their military section because of "not commissioned". Last I've heard that being in alliance remove the commission restriction, unless there's some changes that I do not know. I also do have mods like Vayra's sector and Yunru-related mods installed so I'm not sure if those do affect the game or not.
Any military submarket, or just the November/Automata ones?
If it's the regular military submarket, might be Yunru or some other mod overriding it, unless UAF is doing something hidden. See if you can access the Hegemony military submarket while having an IS commission, or vice-versa.
Mr Modder or anyone can you help me pls? I satured planet so it has like -40 unrest what do I need to change here
"decivSamplingMonths":
"decivZeroStabilityMinFraction":
"decivMinStreak":
"decivProbPerMonthOverStreak":
So that planet will deciv almost now. Like 3 months max. Wanna deciv the whole galaxy 
If you really want stuff to deciv ASAP, set sampling months to like 3, min fraction and min streak to zero, and
decivProbPerMonthOverStreak to 1.
(The logic is in the com.fs.starfarer.api.impl.campaign.intel.deciv.DecivTracker class in Starsector API, for anyone who wants to go digging