Where is the check or balance on this? The executive branch can apparently just launder itself wholesale of any crimes committed by its members.

This is not true.

OLC opinions are just that: opinions. They are non-binding and non-promissory. They are an important factor in any assessments as a norm, but definitely not dispositive and not legally binding.

The only real barrier is the pardon power, but I'm personally fine at this point with totally breaking the seal, trying and jailing every criminal in the administration(++), and consider the pardon power gone for good. Small price to pay.

this sounds like the kind of rules we, as a society, decided to dispense with, so the DOJ can absolutely turn around.