What's even more infuriating is that if you were not British but held a EU passport since you met her before Brexit the British would not have any say about it..
I am French , got married in Thailand 12 years ago and it was at the time a very simple and free process for me to bring her to UK under EU settlement rules
My British mate had to jump through hoops and over over 1k to do the same.
you can rent your condo as a foreigner. Technically you need a Thai person to handle visits and paperwork as this is considered work.
Please note that you won't be able to rent your condo legally for period shorter than 1month ( but you will of course find a lot of condos to rent on a daily basis on air bnb...)
Tell him / her you d like to move out due to the illegal short stay renters next door..
If he / she is higher up than the neighbor things will get sorted out quickly.
If next door landlord is a retired police officer who is having " Relatives over the weekend " Best to move out
If you are doing anything illegal / frowned upon such as being here on a student visa or back to back tourist, working online and so on best not to ruffle any feather and move out