Tell them they are adults and need to start behaving like it (worded more diplomatically). 

Minor or adult? 

hi bpin new yorkCan you get your notary public license to notarize your own paperwork as far as service of affidavits served by another adult but regarding your case or eviction?

Let's not go into how gross the hot tub was for just a few days (but we all know that's par for the course with a large group of adults & kids) and yes, I factor the extra for drain & fill although in this case, it needed even more cleaning.What I'm struggling with is what is the most professional way to reach out to the guest and to write my review? 

Similar for adult children still finding their way.  

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

I have heard Brandon has a property he bought for his daughter to have when she becomes an adult- and he is currently keeping the cash flow but it ultimately will go to her. 

With 3 adults and 2 kids we could have rented 3 hotel rooms, or perhaps 2 hotel suites.  

what if we catered to 8 adults max and 6-8 younger kids?

The only ways the typical investor (defined as a middle-aged adult with 4-5 properties, generating around 60-75k annually) will generate similar yields in the current state is (1) taking advantage of senior debt (assumable debt/seller financing), in this you are improving bottom line NOI via the spread between active and par interest rates. (2) Value-add or flips (Higher risk and not typical) (3) Investing in developing areas that will see high amounts of rent growth over the coming decade due to population changes.