My tenant has informed me today that she decided to sublet one room in my house to her "dog walker" without even asking about my permission.

Since I gave them verbal permission to stay now I have to go through the eviction process to get them out.

You can try to approach the bank to get permission, but I do not recommend doing it behind their back.

I have a somewhat related question, I have section 8 tenant that has her mother living with her (with my permission, btw). 

places ive looked have given different answers to this question with some stating that you have to be present in the state for the closing and notarization while some sites state that "remote closings through audio-visual electronic means are temporarily permissible in Georgia." 

@Sara Bill better to ask for forgiveness than permission. :-)

Although the consequences of bring a pet without permission should have been stated in the house rules.

And your lease should state "no modifications and NO HOLES DRILLED, without Landlord's permission.

The tenant didnt give you permission to keep the security deposit.

Not sure if this strategy is true, but I was told if the AirBNB guest reports the owner as having entered the unit without the guests permission/knowledge (stalking), AirBNB automatically shuts the listing down.