He sounds like a whiny little bitch that overstretched to me.

He has a lot of options. Like selling his house and getting something more modest. Like you said, renting out rooms is an option. Side gig.

He could also reduce how much he is putting in his 401k until he has some other expenses discharged.

WTF is a “parent plus loan”?

That amount for car insurance seems to indicate he may have a history of accidents. Not much to do about that.

See if he can refinance his student loans or car loan to a lower payment.