It just feels like your want is just so niche it's unrealistic to produce the exact phone. If you stopped at wants 1 and 2, sure. When you start adding apps and a bad browser it's veering off into strange requirements because for those things to happen you essentially need to pay for a fully featured phone anyway.

It sounds like you could use an iPhone and only leave the phone, message(disable iMessage in settings), install whatever app or two you want, going settings and disable notifications, or put it in focus mode, or do not disturb mode, or do all three of those things. Then you can go into settings > safari > advanced and disable javascript.