Hi @Jazmin143 welcome to the platform.
Along the way every Airbnb is bound to encounter some issues, a big part of those scenarios is the host's ability to address them in a timely and accurate manner. It sounds like their issues were fairly minimal, and you addressed them appropriately. Things like a fire alarm are out of your control unless the issue is related to the battery or maintenance. I had a guest once that set it off 5 times in their 3 day stay due to continually burning food in the oven. Some alarms are sensitive.
That being said, it's up to you to decide if those issues warrant a refund of any sort. A month seems extreme to me, as again, the issues were rather minimal and solved efficiently. As far as discount, again it would up to you. Personally, I would offer them a bottle of wine or a gift card to a nice restaurant in the area for the troubles they incurred or a discount for the first month in which they experienced the issues. You would have to decide on an amount provide a refund via the platform.
As for the issues with the extra guest and animal. These should have been addressed immediately upon their arrival. Coming in a month after the fact makes it difficult and can appear to be retaliatory or petty. Basically, they are saying "xyz went wrong" and you come back with "well you broke rules xyz." It's not a fight of who takes more responsibility for the problems, it's about addressing them in a constructive manner. where both host and guest satistfied (hopefully).
Ultimately if you feel the guest is not a good fit for your property, you can always elect to end the stay, however they would be refunded a portion of their reservation.
Good luck with everything
