I think his biggest concern is that won't leave much amperage to run anything else. He might find himself tripping breakers all the time, and shutting down his lights without him knowing it.
That is your Biggest concern other than Smell and a landlord visit
And if its his own place then he should hav eno problem running a dedicated 30 amp circuit with 10 gauge wiring. 4000 watts on existing 12 or 14 guage is a pretty heavy load just on the wiring itself