A couple of things: 1 small, 1 not-so-small:
1) When playing as a custom race, I have often been addressed by another race as "[Their short name]" or something along those lines. It looks like a function calling something that doesn't exist (i.e., when creating a custom race there is no place for entering a "short name" or anything like that).
To reproduce: play as a custom race and wait for another race to address you about almost anything. (I don't think this glitch occurs when you initiate conversation.)
2) Saved games are an absolute nightmare. This was a problem even with the original GalCiv and it remains a serious problem with this iteration. Here are just some of the problems I've encountered with save games (some of which I know others have encountered as well):
a) Playing as a "Lucky" race, I was blessed with a "Lucky Ranger." I saved the game one turn later, just in case. A couple of turns later, I accidentally (yeah, accidentally) attacked a minor race I didn't want to be at war with (they were trading with me). I reloaded the game and, what do you know, that "Lucky Ranger" was nowhere to be seen. Probably self-destructed because of my boneheaded maneuverings.

Almost every time I reload a game, the display of my planets' Planet Quality has apparently reverted back to pre-Soil Enhancement, pre-Habitat Improvement, pre-everything levels. I get planets with displayed qualities of 10 having 12 or more improvements on them.
c) Fleets or ships sometimes lose their movement for a turn or even two turns after loading a game. Research seems to take a turn to restart as well.
d) When loading a game, you are prompted to select a technology to research (or keep researching). At times, the technology offered is NOT the one you were working on when you saved the game. If you go with it, your previous research efforts are lost.
Note: out of curiosity, I kept track of four reloads (each at different points in two different games). One of the four reloads resulted in the "d" glitch. The other three were fine.
e) When loading a game, the robot in the initial screen offers the same speech which he used at the beginning of the game. How do I tell that guy that we are far beyond mere Hyperdrive? Maybe this isn't a glitch; it still should be fixed.
I could list a large number of typos. The Humans say something like "hear" when they mean "here" and so forth, but I'm usually too busy enjoying the game to note them all. Maybe later.
But please, please, please improve the problems with save games. I want my Lucky Ranger back!