As a fellow user, as for your third bullet, I would recommend configuring your keyboard so as to be mapped to your target language, so that you can type like a native regardless of the stickers you can see (on your phone of course the letter names also change, which is a plus).
The added benefit is that if you ever need to type anything you will already be set to go it, and it is much faster than clicking a button for sure!
I do it like this also for Memrise and believe me, it is much better! Of course, this is just my advice, feel free to do it the way best suits you!
I fully agree with you in the other two points expressed