Those are lots of questions: The simple answer is:

• it’s all a matter of negotiation. Every client is different and wants different things. Even if I tell you every detail of my contracts it won’t help you, because you will get a completely different one. Just try to get the best deal for yourself.
• There is virtually no chance that I don’t earn anything while working a lot with this business, because I get a percentage(minimum of 10%) of every booking. And even if not many are booking I get the referral money from Airbnb.
• Airbnb doesn’t mind, I think, they even have an option in the settings for that.

Thanks for reading my article, hope this answer helped.