Not a full answer, but...
People do bury the stuff but I don't see anything off-hand the either permits or prohibits it (other than the cable's ratings) and I don't think I've ever run into direct-burial rated SOOW.
That said, I've put it in shallow trenches, back-filled with clean dirt and where there was no vehicle traffic, and the AHJ didn't complain. That was for 2-3 week installations, not for long-term/permanent. With the better availability of cable ramp in the rental market, that's a much better solution than trenching.
If you need permanent, there are cheaper DB-rated cables types than SOOW.