I understand the 9 plats, but not at his level. He's trying to make it so that if he dies and uses -rv he loses no plats. I do it myself, because there is little use in spending 10m+ because you wanted to revive quickly. He probably didn't use JUST nation, he could've had his summons killing stuff while he stayed near the material converter to get more plats. I find this legit, had he really hacked/cheated his way up, he'd probably have better gear, many more plats/arcs, and he's probably leveling with someone on Hell stuff-with even higher Int than he had (and over level 900) I needed updated Summon Improv to kill any type of thign in Hell, those Lords of Plague would mess things up too much for him to have been alone.
I doubt he's a hacker, the time is a little questionable, but is theoretically possible. (Levels are fast at Medeans in normal world, plus EXP tomes are seriously awesome.)