I'm certainly going to try but getting enough troops to some of the island nations, especially Japan and England, is going to be quite difficult. Capturing the Maldives was tedious, and I lost that purple island up in the arctic to a damn peasant revolt because I physically couldn't get to it.
I've captured a merchant republic that popped up in the duchy of Funie in Manchuria (same religion thankfully) and subjugated Amalfi, so I have ports in both halves of the map, but still pretty limited boat-wise. A Suez canal portage type of deal would be amazing, but I don't know how realistic that is for the CK2 timeframe. I imagine not very.
This is my first time playing as a horde so I'm learning a lot, like that I can't grant counties to non-nomadic vassals which means I can't create new Merchant Republics. I don't care about the money. I'm building Great Works in all of the counties around my capital as well as all of the Tengri Holy Sites just to have something to spend money on. What I need is ships.
Ship! A ship! My Khaganate for a ship!
Luckily a dude on reddit pointed me to the Pillage All Holdings mod so I don't get carpal tunnel so I've got that going for me which is nice
I also haven't come across any bugs in this playthrough so far, though the game sometimes gets VERY frame-y on the Great Works screen for whatever reason.
Oh also, maybe a suggestion if this isn't already a thing if its at all possible. It isn't relevant in my playthrough
yet, but the decision to become Genghis Khan is only available for rulers of Mongol culture if I am correct. I've looked everywhere and Mongol culture has completely died out in this game. This means its impossible for me to claim the Title of Genghis Khan, which (if I am not mistaken) in turn means Temujin is going to spawn in the middle of my uncontested territory with enormous doomstacks "intent on uniting the people of the steps" which is BULL S**T because I've clearly already done that.
Again, not relevant to me yet because of the year, but it would be nice in my fairly unique circumstance to somehow be able to claim the moniker of Genghis Khan for myself without Mongol culture or otherwise prevent him from spawning when his stated reason for spawning in-game is irrelevant.
EDIT: I just got Iceland and the Faroe Islands from a great holy war against Norway, so that's part of the island problem dealt with