Some of the mongol bugs that I’ve experienced include:
I have a few too + some annoying stuff:
Lately, I had quite a lot of games when I in the late game wanted to move my buildings (mostly ger and landmarks) but I couldn’t and I couldn’t find a reason why. I thought landmarks have some kind of timer which block packing landmarks because of how annoying it can be to destroy Mongol landmarks (once we were 3 players vs 1 Mongol which was left with one landmark and played hide and seek for like 8 mins) but since I couldn’t even move ger that felt really weird. It usually happened at Age 4 but sometimes even Age3 and with a post of @TehLemone, I realised it is probably because of the max population.
In one game enemy Mongol packed all buildings after his army was destroyed and forget a few of them to move them but I wasn´t able to destroy them before he started moving them because rams can´t attack packed buildings. Probably as in problem above game takes packed buildings as units.
Can the first sheep be fixed so its not bugged at place and either follows TC or Khan. Khan would be better since sheep kinda always buggs unpacking TC if it follows.
With above in mind. Unpacking buildings can take really long time to manage and its annoying. Like when you move even ger quite often it happens that it wont build just because of some random villager walked over it and it doesn´t try again. (It s starts unpacking but unit steps into so it waits until unit moves away but when it does unit can move again into and that cancel whole process). Also quite often when I have to move for example 15 pastures usually I have to click each one invidualy and select place. And if you click one wrong you can stop building another. It would be nice to be able to it with just one button for same buildings or with shift or something. Sometimes it works that I just click with mouse but sometimes it doesn’t and if there are different types then it doesn’t work at all. + if I moved TC at which I have gather point of sheeps then sheeps will cancel building TC.
I think that it should be possible to pack buildings that are doing research of technology. Almost everygame I have to decide If I want to lose like half of time on research in Steppe redoubt because I´ve mine all gold and need to move it. And it means a big delay in that moment because I have to cancel it and start it somewhere else but ussually I don’t have where because in that moment I ussually have two ger which are doing reaserch as well. So stopping it middle + travel + the part I have to control army usually means like 4 min delay for me in that reaserch. So it would be really nice if I could stop research by packing it and when I unpack building it would continue.
Sometimes I sent villager to build ovo and villager will just walk to it and stand there. I have to click it to build it again. (I m pretty sure I´m always doing Q Q click)
If I research Siha Bow Limbs with stone it still shows icon for that upgrade with stone but you cant research it again.
Would it be possible to like set target for Khan and Mangudai? For example I want with Khan to run next to enemy scout so I´m able to get sheep but while doing so I want Khan to attack sheep enemy scout have. Or I want with Mangudai kill villagers/ trades instead of units that are chasing me but that means stoping or work with them like with rus horse archers… So raid are not so effective. Or I just want kill first archers instead of spearmeans.
Why I can ´t with Ovo, Prayer Tent with Monastic Shrines, or The White Stupa double produce ships? Or why docks don´t upgrades with stone? Like even odds of finding stone near water to do that in early are so low and without it at water maps stone is mostly just for upgrades since its not in my opinion good to waste good position of TC for double production of vills and to waste 150 wood at it.
Could be possible to like load Khan into any military ship (maybe even everyship) and after it would become Khans ship which would have option to buff shipps? From my games I use Khan at water maps just to kill wolves and to find first deep sea ship - kinda waste of 1 pop.
Could be into game learn be added what upgrades do if you use stone?
Yeah the unpacked buildings can be quite buggy, it feels counter intuitive that you can’t shift queue them to unpack, but I can understand that poses a question of in which order do you unpack them if doing that, however it feels better than not being able to, especially if all selected carts are of the same type.
Further to this if you pack a building and it was a part of your buildings bound to a hotkey, upon pressing the hotkey you will see the packed cart’s UI, so are unable to produce units anymore using the key. This should be fixed to just continue displaying the normal building’s ui imo, as otherwise you have to rebind your buildings or wait till they’re unpacked. Also as you mentioned, packed buildings do count as a pop, so it becomes a hassle trying to free pop in order to move a landmark such as the Kurultai or Deer Stones mid battle for their buffs. In my opinion it would make more sense for them to not require a pop, which would fix the issue of them being deleted if cancelling their unpacking when pop capped also.
As you said its also quite a hassle to get your khan / mangadai to do as you want, for example if scouting it would be preferable for the khan to be “passive” and not alert the enemy by attacking them, or have the khan kill a scout’s sheep, or deer that a rus scout is trying to kill rather than it auto targeting the scout.
Although not a bug, I also feel like scouts / horseman should be a little faster than knights, considering that they are more heavily armoured and can beat them in a fight it would give them a bit more utility being faster 
Yea also spying with Khan is impossible. Like I wanted to see enemy army movement while being with my Khan hidden in the forest but I wasn’t able to do that because before I clicked to V(stop everything) he managed to fire a shot. And also I would like to have the option to not kill all wolves at enemy territory.
Just scouts should have buff for movement speed he has 1,62 horseman has 1,88 and lancer has 1,62.