@Max Tanenbaum excellent point about the puppy vs adult and the landlord reference. 

I have a 5 bedroom house that I am currently renting to 4 adults and 2 children. 

I suppose for any situation with more than one adult tenant, it would be a good clause to include.

Listing all adult occupants on the lease as jointly and severally liable is the right thing to do.

So, maybe two adults and one kid, vs two adults and at least two kids.And families with extended family living with them, are unlikely to be looking for a two bedroom, one bath home.So, my vote is to leave it alone.  

There is no inventory around Seattle but I will buy in the South and South East states.3) I agree that you can't change adults for the most part.

Maybe, adult diapers, Depends The turn key companies are in business to make money, and the longer they have been in business the more money they have made.

It's two completely different ways to pay the same money.I don't know, in the end it doesn't matter if you guys get it, I'm just astounded that a group of adults who think they are financially savvy can't get this.

While I generally agree 'once a dead beat - always a dead beat' - but seems they are trying to change their situation: selling a 1500 sq ft house to rent an 1100 sq ft house (with their 3 adult  - college bound - kids!)

Anyone who is not an owner of the property and is an adult is a tenant or legal occupant, and if they refuse to leave, you - legally - have to go through the appropriate eviction procedures.You could lock him out, but if he gets a lawyer and fights it, you'll have to let him back in and evict him properly.