Non-quick release through axle - a few questions
It's a Maxle Stealth. They are a little cheaper and are also a weight savings thing. They're not super common but there's nothing wrong with them. They've also not been around very long, just less than two years as of now.

As I understand it, on the Rockshox forks that Maxles are more typically found on, the Maxle Stealth versions are fully cross-compatible in all cases with the quick-release Maxle Lites and Maxle Ultimates that share the same dimensions. So for example, the axle you have mainly exists in the world to be retrofitted unto RS Bluto forks with the Maxle Lite that has all the same dimensions. So it's probably physically compatible, but you should probably double check with the manufacturer before doing it that there are no hidden gotchas.

(Edit: One such gotcha could have to do with any pronounced recesses or grooves on the fork that the shoulder of the Maxle Stealth sinks into that a lever might interfere with. Just hypothesizing.)

For the torque, it's really a pretty wide range they give you, so I wouldn't worry about it too much. On the tight but not strenuous or aggressive end of what you could do with a standard allen wrench is a good way to think about it.