Some more thoughts:
11. The colonizing planet window has some overlapping UI elements. I'm sure this is WIP, just letting you know if you weren't already.
12. The tooltip on the "Expand the Council" agenda is a bit over-aggressive at preventing spoilers.
13. The nested tooltip system should be including building details. A new player would want to know what an "Orbital Filing System" (or any other module/building unlocks) actually does.
Some of them are missing effects entirely. The main point of Hyperlane Breach Points is actually the upgraded Hyperdrive, but that's not listed at all:
Also, this is supposed to be a Tier 4 reward but apparently the UNE starts with it as a guaranteed research option already? It shows up on my Physics Tech options. What happens if we research this before unlocking the reward? Do we get stored science?
BTW, I'm still Expansion focus 13 years into the game and 4 out of 5 of my Empire Focus tasks are Combat-oriented. The Focus Task category weighting is off. (I do appreciate it retroactively giving me credit for something I did before the task popped up.) I'm at 40/50 Exploration progress but can't really continue unless I burn my unity rerolling tasks or dumping alloys on these combat tasks that I'm in no rush to complete (apparently no neighboring empires on default galaxy settings).
14. I think the Empire Size pop contribution is busted. Looks like it's dividing the total pops in my empire by 100 for the display, but the formula is also using a fraction of the expected value. On live, 61 pops would be +61 size pre-modifiers. Here I'm at 0.2.
15. It was not obvious at all that to modify my planet's existing zones I would need to click on "City District" instead of the zone I want to replace.
16. The City Zone slots ask me to add a new zone even when I can't afford it.
17. The Timeline looks like it has way more room to display stuff than it does. This screenshot was taken after I completed a first contact in 2205, but I have to click the arrow to see it. Zoom buttons don't seem to do anything?
Also, I think "held elections" should tell me who won the election.
18. Speaking of First Contact, there was a one-option pop-up event telling me about it, then clicking OK didn't open the First Contact screen. It just unpaused the game, and there's no notification on the top bar anymore. I had to click on the blue First Contact icon around the system to actually assign my envoy (which I only knew to do because I've played before).
19. Is there a way to move buildings between zones? You can build whatever you want seemingly in the Capital and Urban districts, so I put my first Research Lab in the capital district to keep my zone options available (I built a separate building instead of replacing the basic lab to see if the +20% applied to basic researchers, which it seems to). Then when I later decided to get a Research Zone, I couldn't put anything in it because the lab buildings are Planet Limit: 1. I'd have to demolish and rebuild my two lab structures.
20. I can't see how many pops are in each strata without expanding the strata. This is especially important for Civilians which currently don't show up cleanly elsewhere on the UI. Unfortunately, this section auto-collapses every time you navigate away from the tab.
There technically is a tooltip if you hover over the "available jobs" number on the summary screen, and I think the number of Civilians there is accurate, though it lists a bunch of other jobs I don't actually have (like "Hunter-Gatherer: 0", twice). I also found this tooltip by accident; I wasn't thinking to check there.
21. I don't know what to do with Energy anymore, since it's not used for trade. I haven't built any Generator Districts aside from the start and I'm already halfway to the storage cap. It seems like for organics, Energy has lost a lot of value. Yeah, it's there for ship and building upkeep, but it's way easier to find space energy than it is to spend it in the early game, which is a marked shift from before.
(Yes, you can trade it away, but I don't like mass trading for resources on live - a resource only good to sell on the market is a resource lacking a good gameplay purpose - and I don't like losing out on the 30% fee twice if I can avoid it.)
This may be different for machines, but gestalts are stated as not ready yet.
22. Colonization seemed to be quick, at least in the early game. I didn't overbuild my capital after reading this thread and it seems my two guaranteeds colonized in about the same time it'd take early-game on live. Since accurate pop growth numbers aren't visible, I can't actually tell how well pushing to the colonies is doing vs on-colony pop-growth. I am using "Colony Designation" for both colonies despite being able to pick others because I was hoping to disperse more people off the Capital, but my Capital still appears to be outgrowing migration.
23. I don't know if the Expansion Tradition's +100 pops actually applied. I don't think I got them, or if I did, not sure if they spawned on the capital or something. They certainly didn't appear on my colony.
24. It's early but getting a bunch of "your leader hit level 3" notifications without getting the trait pick kinda was disappointing. The bonus pick option we got at level 2 didn't seem to help much for my Ruler who barely had any council trait options (is this a Democracy thing?).
25. I remember seeing the notification for an election, but not one with the outcome of the election. Did this get changed to a toast or did I just miss it?