Note: all games played were set to difficulty Immortal (7). This beta has a lot of crashing problems, so no games were completed to the end, but I was able to try out some races extensively.
Murlocs: I really wanted to test this race because of their inability to build ships. However, the first time I tried them, the game crashed during the loading screen. The second time, after a full computer restart, I got it to load fine, but the display for what tiles the citizens were working in the city view was buggy, covering the tiles they were working in a white and red checkered pattern instead of displaying yields. I kept playing anyway, since actual yields were not effected, only the display. The game then crashed shortly after I hit the "next turn" button at the end of my first turn. LUA log from the second game here:
http://forums.civfanatics.com/attachment.php?attachmentid=365391&stc=1&d=1385509201
Murlocs try #3: Restarted the computer again. This time, I did it on a duel size map to leave less room for errors. I managed to get well past the 1st turn, but the bug with the civilians working tiles in the city view remained. I was able to try out the race well enough before it crashed (when I clicked on the Civilopedia). They do NOT have extra embarked defense, despite what the race description says. This made it very hard to fend off barbarian ships, since they kill all land units in the water and I can't build my own ships. This will probably be the weakest race without a custom type of embarked defense that is even stronger than the War Canoe and Amphibious promotions that the Songhai Civ receives. LUA log from the third game here:
http://forums.civfanatics.com/attachment.php?attachmentid=365392&stc=1&d=1385509201
Naga: I love the loading screen and I hope it doesn't get you in trouble. Heh. This is a fun race, but they are far, far too strong. Getting a free tech AND a free policy for female heroes creates a snowball effect that makes it easier and easier to build more and more wonders containing female heroes. Since two of the three starting Naga heroes are female, I was able to take Pottery and Sailing for free and start working on Skovos from turn 1, guaranteeing that I would not be out-built. Since the first hero is free, I also started turn 1 with Colonialism already opened. The next policy I took was the one that not only boosted wonder production, but allowed me to hire my second female hero for free immediately so that I could immediately get the policy which doubled palace output, also for free. Long story short, I was crushing everyone with my heroic female royal guards, decked out with full Shamanism, before anyone else had gotten out of the classical era. I suggest you either remove the free techs or remove the free social policies to balance this race. One is good, but both is too much. It will need one tiny extra benefit after that big benefit is removed, though. Maybe take away the free tech one, and then also add a slight culture gain for succeeding with Allure, haha.
Tauren: About as powerful as the Naga will be after the Naga are modified as I suggested. A solid race with a superior religious start thanks to the turn 1 great tile providing faith. A smart player will start with a Great Scientist or a Great Engineer. I started with an Engineer to ensure enough production to secure the next wonder. That early extra 4 production was very helpful, but not overpowering, especially when compared to The Dominion's abilities. Good stuff.
Troll: Played this one on a duel map as well. Heroes that start as Shadow Priests correctly receive the two Medic promotions and the March promotion, but heroes that are promoted to Shadow Priests only receive the Medic promotions, no March. This can be solved by getting a magic ring, but those take time to get, and heroes are missing out on a core ability until then. I was in the middle of building up for an early war when it crashed for no reason at the beginning of one of my turns. LUA log for that game here:
http://forums.civfanatics.com/attachment.php?attachmentid=365393&stc=1&d=1385509201
Primal Zerg: Spain + America. Like Spain, they're great if you can manage to find a natural wonder that isn't claimed yet. Without that, they are a tad lame. I noticed that you moved the zerglings from Kerrigan to Zurvan, which makes complete sense. I like the idea you had with the Spawning Pool, but I don't think it's enough. Zerglings are very good by scout unit standards, but still technically weaker than warriors. 2 free units is not enough to make war with, and even if you just want to explore, you're still mainly using heroes to claim goodie huts since the heroes are the only ones who can choose the benefit. To get the true "zerg rush" feel, I think that Spawning Pool should create 3 or 4 zerglings rather than 2.