Republics still getting eaten by Kingdoms

Amalfi and Gotland both disappear during the game's timeline, so I don't think that's necessarily such a bad thing. It would be nice if it was easier for them to swear allegiance to a stronger liege, though. I started a game as Lubeck in 1337 and inadvertently wound up independent from the HRE after a civil war that I wasn't involved in (that bug still hasn't been fixed!). Because Lubeck is a titular king-tier title, I don't have an option to swear fealty to the emperor, so if he decides to take his land back I might be in trouble.

Also bear in mind that republics are much more powerful than feudal realms of the same size, so giving them too much help would just make them run out of control again.

Yea if they get a foothold they can still go nuts. Just watched Amalfi take over Napoli, then Palermo and Messina. It was fairly early in the game at that point, but with those 4 counties they had the 5th largest army in the world and a lot of money for mercs. Took some real effort, opportunism, and money (mercs!) to break them back down.

Then again, I watched Genoa start to get big in the same game but do it via Africa which pissed off the Sunnis. Next thing I know they are in 4 wars and get demolished between Africa and Italy. Venice still lives though!

As far as Venice goes, making them part of de jure Byzantium is just asking for trouble.

I've created Venice and after 101 years, they have barely covered Adriatic sea with trade posts.

I think that, aside from fixing republican bugs, maybe the cost of trade posts should be reduced a bit, at least for the AI. I tried playing as a patrician in Genoa and after a few decades (and a dozen wars with Pisa and/or it's patricians as agressors) I was the only one approaching the trade post limit. Two families had 0 tradeposts, one had 1, and the Doge, despite theoretically being the richiest had only 2. Granted, the tradepost in Nice has been lost 10 times or so (Pisans love waging war for it, despite the fact that it gets destroyed, not transferred upon ther victory), but it's still weird that the limit seems to be mostly for the player.

Every 867 play through where I am not involved in the Mediterranean has Venice devoured by the Byzantines. Sometimes, it comes back as a Greek duchy-republic. Other times, the emperor holds it for the longest time.

867 also has the issue that Republics don't have the trade technology to make more than a couple trading posts for a long time, so they can't start rolling in the money as easily as in later starts. But yes, Genoa in particular always seems to get eaten in my games.