For your first point - it actually makes me happy that Google does not intentionally (illegally?) promote their own products over others in the app store. I assume their app is following the same algorithm as others to determine how it shows up on that list. Since it just launched, it makes sense it's not at the top. The ranking should improve.
For your second point - I also had the same error when I launched it. Closed it and tried again and it launched no problem.
APKMirror has it, and it can be installed from there...
...but then I get "Location not supported" when I start it. Helpfully suggesting I use Google Assistant instead.
My main reason for trying Gemini is that I hope that it makes fewer errors than GAss, and be more powerful too. Operating Assistant's voice controls in the car might be more distracting than just typing. And that's just for reminders and Spotify playlists. Anything more powerful is completely impossible.
For people who don't get this: Google has insane internal power struggles and siloing that lead to all manner of dumb inconsistent behavior across google. It would not be unlike google for the "Play team" to have their hand in some other internal AI (or be anti-AI) and therefore carry a degree of hostilitly towards gemini.
Same experience. I launched Gemini a second time, and it worked. The first message about "Gemini isn't currently available" was a bad first impression.
One thing the app really needs to be able to do is auto-submit when speaking to it. It offers to replace google assistant, and after trying it out for a couple minutes, it can replace assistant, but I have to manually click to submit each instruction instead of just talking to my phone.
I tried on iPhone, saw all the different apps that aren't Google, then re-read the announcement and saw that I should be able to see it in the Google app. So I load the Google app, but for the life of me I can't figure out how to access Gemini with it. Go online, find a news article with pictures, see that the 'switcher' above the Google logo does not appear for me, and then give up.
I can access it via gemini.google.com and I'm logged in to the iOS Google app as the correct account, no idea why I can't see the functionality on mobile. Oh well. Maybe I'll stick with OpenAI a while longer.
Scroll past the screenshots of those apps
Scroll past the Limitied-time events
Scroll past the You Might Also Like and Similar Apps
OK now we see it, we install, it we launch it and..."Gemini isn't ccurrently available. Try again later."
Bravo Google. Great launch.