(a) War weariness increasing after end of all wars in single citys. There is a discussion on steam forums about this bug. The solution is to reload the game and make one turn, then the war weariness is corrected.
(b) Two units (2x Horseman) on one square. When moving the first one unit away from that square the game treated the unit like it was standing on an adjacent square instead.
(c) Unit costs completely off. Unit A production costs displayed as 90, Unit B as 180. Unit A takes 1 turn to complete, Unit B 8 turns. This problem has been reported on this forum as well.
(d) Trading deals sometimes off. Leader A suggests a deal. He wants to give me a certain resource for 30 turns (among other things). I right click on that resource to delete it from the deal ( I don’t need it). Now the (better) deal is not acceptable to Leader A anymore.
(e) Cycling units "forgets" some units. The "end turn" message sometimes appears even though some of my units haven’t moved in that turn. This way I sometimes forgot i.e workers for a move or two. This bug I haven’t seen reported elsewhere so maybe it is not a bug and instead I a am missing something.
Since we're all programmers here, my take on the above:
a) Obviously their logic for clearing up war weariness after a war isn't done at the right time, and there's probably some flag in code that's not getting set properly. On reload of the game, presumably it initializes to a new value that will let the WW clear over time. Sometimes these bugs are easy to track down, sometimes not. This is also a case where the UI on the city's penalty could likely be clearer, in which case it might have been more obvious (hey, this has said I'm going to have a WW penalty for the next 20 turns, but it's been mentioned as 20 turns for a few turns now. Wonder if we have a bug here?)
b) I haven't seen this one. Could be a simple case of they did the 1upt rules up assuming they wouldn't get in a bad situation, then someone added Scythia and didn't notice that things were off in some movement rules. It should be very rare to end up with multiple horsemen on the same square, and it could be something in that first movement that they didn't expect. The number of cases of this might be very small, since it's highly possible they didn't do a ton of debugging playing as Scythia. I mean, you run it enough to check that, yeah, you can get the double horsemen, but especially since there's the +100% production/disbanding unit problem, yeah, it's possible they lacked QA coverage on this
c) Overflow. Again, they should be more clear in stating that you have carry-over from a previous build, but civ has kind of always been bad about this. They also will re-arrange the governor when you queue a building, so sometimes I might see "settler 4 turns", then select it, and suddenly it would move to 3 turns.
d) Honestly, to me this shows that they actually spent time trying to build a trading system. If they just had a simple "1 resource = 100 gold" then you don't see bugs. But because they tried to be a bit more fancy, in weird cases obviously some resources end up getting negative valuation. Again, could and potentially should have been caught in QA, but this is also the sort of bug that might have been noticed too late, and you worry like heck about breaking things at the last minute, so better to leave it in than potentially make it worse.
e) Definitely some weird issues with the cycling. But again, that could be the case of "oh ****, let's not break this more right now".
So from my take, yeah, there are issues. And yeah, a lot of these issues could have been caught in QA. And it very well likely was pressure to get things out on time at release.
However, when I view issues like these, I also take comfort in the fact that THESE are the bugs that we're complaining about. We're not complaining that "the game crashes on me every 5 turns", or that "I captured a city and suddenly I can't move my units" or "I went in to capture a city and suddenly my tank disappeared". So yes, while we might be complaining about issues that could very well only take 5 minutes to fix (and then 4 hours to test), the fact that we're not seeing major, core, structural issues shows that they at least got through the biggest of the problems.
It will only be after the first patch that comes out that we'll truly be able to start making declarations about the state of the code. If it takes them 2 months to come out with a patch and most of these minor issues aren't fixed, then people can complain. But for all we know the next patch will be released in 2 hours from now that fixes all these bugs and more, because the code actually was in great shape but they just barely ran out of time before release and were too scared of screwing something up on release. Especially for a AAA game, it looks a lot worse if they have to come out with a day 0 hotfix because of a major bug, so I'm guessing they're a lot more strict on code freezes as I am working for a small indy game studio.