I don't know if there has been any progress on this or if you have heard back from Airbnb or from the guest?
This is a tricky one because, from what you have described, the guest isn't breaking any obvious house rules (unless there is something else you haven't mentioned?) so that might be why Airbnb is not being terribly helpful. I have had to call Airbnb twice in the past to ask them to tell a guest to leave and they were very proactive about it and backed me up completely. But, in both situations, the guest was in clear violation of my house rules. In order for them to act, they need to see this, i.e. the rules that are being broken are clearly stated on your listing, and the correspondence about this is on the Airbnb messaging system.
The most alarming thing you've mentioned is the confrontation with the cleaner, so I agree with @Clara116 that that is what you should focus on. Tell Airbnb that it is NOT okay for the guest to frighten your cleaning staff to the point that they refuse to come back. Tell them you have sent an alteration request but the guest is ignoring it and you need them to contact the guest, instruct her to leave and cancel the booking penalty free to you.
Also, while it's useless to say could've, would've, should've in hindsight, going forward, please do vet your guests more carefully, ESPECIALLY for long term stays, and never ignore you gut feeling (I have always ended up regretting it when I have). What, by the way, gave you that bad gut feeling in the first place? Also, what did the review from the other host say about her? Perhaps there is something in that review that could help back up your case with Airbnb.
I also don't understand the thing about the horse pic. Hosts cannot see a guest's profile photo before they accept the booking, so how were you able to see that?
In future, do make sure you read not only all of the guest's reviews and look at their star ratings, but also the reviews they have left for previous hosts, as that can sometimes be telling. I am far more likely to accept a guest that leaves lovely reviews than one who never bothers to or who is constantly nit-picking.
Make sure to have a proper conversation with them, e.g. if they have given no or limited information about themselves on their profile or in their message to you, then ask for it. Guests who are then non responsive, evasive or defensive, are usually a bad bet, or just not worth the risk. Ask them to confirm they have read, understand and agree to your house rules. If there is a red flag, pay attention to it. If you're unsure, ask more questions about whatever is making you feel uncomfortable.
I know that Airbnb only gives us 24 hours to make a decision, which doesn't help, especially when the guest doesn't respond quickly, but it's better to decline when in doubt than go through the pain of a long stay with a bad guest.