Good afternoon!
Could someone tell me whether it's realistically possible to book a taxi in Stepantsminda (for trips to nearby villages, not to Tbilisi) using Yandex Go, Bolt, InDrive, or Maxim? Or should I only count on finding drivers "on the street" or at the local taxi stand?
I've checked Yandex Go — it lets me select a route and even shows a fare, but then says "No cars available."
Hi! The roads there can be such that it's better to travel with a local driver, preferably in an SUV.
But to Arsha or Gveleti, for example, the route follows the E117 highway (the Georgian Military Road), so that should be a decent road, shouldn't it?
The highway is fine. You can easily drive it in a regular sedan.
I highly recommend visiting the Truso Valley, but for that you'll need an SUV.
And how do you find these local drivers? Just stop people on the street? 
When it comes to SUVs — yes, pretty much.
The only thing is that pricing can be rather chaotic, so make sure to ask several drivers before agreeing on a price.
There are plenty of private drivers in Stepantsminda, especially around the central square. I can't really advise on current prices, though.
There are lots of SUV owners there who take people up into the mountains.