I doubt the City will turn down your proposal with this on going housing crisis in Portland.

Are you ever afraid of legislation against AirBnB?

I don't see where you're located (every State has different legislation) but in my market, all three of the criteria you mentioned would be unlawful reasons to decline an application.

To be honest - I can't think of many others in this instance.The reason it is that way is because the legislation is meant to eradicate discrimination in society. 

I would like to write him a sample proposal but I'm not sure what to put in it.

Think a list of qualifications that applies a weight to each trait:Credit Score - XPets - XIncome - XPrevious recommendations - XLength of proposed lease - XDeposits - XTransunion gives you a go- no go decision but the above may help you grade the quality of each potential tenant while being objective.   

The City of Charleston has had the hardest time with their regulations, but I think they're nearly done with their proposals and will be enforcing some rules soon.

If you don't know what you'd like 5 years out then people are going to be proposing a lot of possibilities that won't have ground to take root in.The fact also stands that, without W-2 income, financing can be very hard without a lot of cash or a proven track record in real estate.

You'll have to get creative with your proposals to investors about partnering.

You can find the same in any industry or field where any proposal for change is met with a bureaucratic system to determine the absolute best way to do it.