I hear what you're saying but I've honestly never come across any of these bugs. Taking advantage of tradable items typically requires some impetus from the player to purposefully alter the deal or make multiple deals to get the biggest possible take from the AI. In the case of peace offerings, their initial peace offerings are fair, at least in the sense of being consistent with peace deals they've given in prior patches. So for someone to encounter this bug is to purposefully try to extract more and more favorable terms from the AI. I don't do that. The game is easy enough and I'm not interested in getting victory as fast possible or doing Deity challenges or anything.
I've to say I am with Lily in this one. I'm not exploiting trades, and because of that, this bug is annoying as hell (even if you encounter it only seldom).
Situation is: you might want to end a war early, because it's just annoying to keep focusing on units and be distracted from everithing else (be it religion, building or expanding in a different direction), but you want as well to get from the war some cities that for you have certain strategic meaning (empire continuity, access to a specific sea, access to certain resources, etc...).
Normally, the AI offering peace should be an opportunity: they want to make peace because you're superior, so let's make a deal: I'll get some cities in exchange for the peace. Of course cities will not be part of the initial trade deal, but why not?
Before october, I was able to get a "fair" trade for some cities that were not strategic for the AI (small cities whit duplicate resources -for them-, mainly). And by "fair" I mean paying around 100 gpt. in example. (It's ok, my treasury can handle it, and if I get less focus on war and the economy running that is just peanuts).
But with the bug that Lily mentions, asking for a city immediately gets you peace, and the city at no cost (and you can ask for all cities). Asking for all cities would be an exploit, of course, but being denied a "fair" land for money deal because of this just means you need to keep warring (or exploit the bug) if you want those cities. Not fun.
So, maybe it's not a gamebreaking but indeed a bug that impacts gameplay and should be considered.
Edit: (added just in order to not double-post)
Now that we are at bugs: ¿Anyone noticed if Gilgabro can make alliances whith Heroes & Legends mode enabled?. He is in my current game and it looks like alliances are not available for him. ¿Maybe it is a secondary effect for his ability change?