The parks accept only dogs for the blinds. So if you do not look “ill” (physically I mean) do not expect them to accept your service dog. There is a good reason: parks are filled with reptiles and wild animals (cats, turtles, monitor lizards) 🙂
Many people have dogs in Bangkok and we can cope with the limits. (I have one)
you can pay taxes on rental investments. They don’t always expect foreigners to pay (but they should).
you will be registered with a tax ID. I am in the process of doing it and a few friends just did that. We are all on elite visa but I think this might apply for the other long term visa as well. Real estate income are treated differently than other kinds of income usually. I will investigate more.
it’s possible to rent as private individuals / owners. If individuals start to have “too many “ (which might be 5-10-15) homes then it might go under the “business” flag. As long as individuals rent long term, respecting the rules (no short term) everything should be fine, according to law and personal experience.