Unless you believe both of those should be legal as well, then we're at an impasse.
What about a drunk girl trying to get away from an assailant? Or any other situation where the risk of getting pulled over is worth it?
In your example, what if that drunk girl proceeded to kill a family of four in her attempt to drive away? Or started driving on the wrong side of the highway in order to escape?
You could make up any number of scenarios to justify breaking any law. The obvious solution in this case is to add an emergency override which unlocks the car and also calls the police. Because if you're going to bypass the drunk sensor, you better have a damn good reason for it.
Not wearing a seatbelt doesn't really affect anyone else, so it shouldn't be illegal IMO. However, I could see an argument for insurance refusing to cover you for medical injuries if you weren't wearing a seatbelt.
Texting and driving is a bit different and I would consider that "reckless driving", which already is an infraction. If you're operating your vehicle in a manner that is unsafe to other road users, you should have your driving privilege suspended. However, just making it a fine makes it seem less serious IMO, and handing out tickets for innocent use of a phone while driving also seems wrong.
If you're not endangering others, you shouldn't get a ticket. I think this should apply to all infractions of the legal code. If you're driving over the limit, but there's nobody around, then you either shouldn't get a ticket or it should be a much smaller one. However, if you are endangering others, the penalty should be far more severe than it is today.
The same goes for alcohol. There are a lot of other ways for you to be driving dangerously, but being slightly over the limit is often safe for many people, while being under the limit could still be dangerous for others. For example, driving while sleepy is often more dangerous than driving drunk, yet I don't think I've heard of anyone getting their license suspended for driving sleepy. Also, driving with screaming kids is also dangerous (as a parent, I've been there).
You should only be pulled over if you present a higher than average risk to other drivers, and that needs to be proven independent of things like your BAC. I don't think, but I also don't think it's fair, especially since some state levels are quite low (e.g. I live in Utah where we have 0.05% limit).
And even if there's 'no one around', that relies on a judgment call made while drunk and impaired. If you told a lawyer 'Sorry, I didn't think anyone was around when I drunkenly drove into them', you'd be laughed out of court and straight to jail.
Which is why they're illegal. If you drink and drive, you've established that you're putting yourself and others at danger while driving. The same can be true of driving sleepy, but that also happens at a far less rate statistically than driving drunk in the US.