She’s the ‘lessor’ so if the read the requirements it says you can use that, in her name, with her ID number and contact details (and probably your number too). You’ll probably also need letter from her confirming you are staying with her the whole time.
Someone who wrote on this site sent their dog ahead and had them lodged in a doggie hotel during quarantine. There are expat services that deal with this in Bangkok
It's inaccurate to say British people 'can't come' - as the article you quote says it's a 'proposal' before the government. It hasn't yet been decided one way or the other.
If you can get a retirement visa in your home country it can be better because you don’t need the funds to be ‘seasoned’ in Thai Bank account, just in your home account. But it is possible and quite easy to do in Thailand too (through seasoning).
Not sure. Mine was in English. The school or place you are going to teach should be able to advise. Or immigration, or your Embassy (if they will notarise, many won’t).