The biggest similarity to the AK is the piston/carrier/bolt design, which is definitely AK inspired. From there, it contains elements of the AR and FAL.
Rugged and reliable as the AK? I don't know if there is enough data out there to draw a conclusion, but I doubt there is anything to this day that will run as long as a well built AK.
It can be maintained easier than an AK: detail strip and all major parts replacement done by the user with common tools.
I'll leave the other questions for some other folks.
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