"We built the phone in between" [a smart phone and dumb phone] is a pretty appealing tag line. In the last half of the 2010s, when I finally dragged myself into getting an actual smart phone, I really wished I could get a flip phone that was more capable. The feature phones still on the market at the time seemed to be right out of 2003.
This implementation seems a little off. It has the flip form factor, and can run most android apps, great! But then it sounds like they arbitrarily block browsers and 'social media'? I think just leave them out by default, and let people go that route if they want it. The form factor already limits how well some of those would work.

I like to try and pick a mix. I've been leaning more mage lately. Sometimes magic is super op, sometimes it's just an interesting system. Sometimes it's neither tho, and just clunky. So it's really kind of a toss up on whether that's a good decision.
Warriors are probably the best pick lots of times - just because gear systems often incentivize them. Finding a cool sword or shiny armor isn't very exciting when you're just hurling fireballs all the time anyway.