It's the SAME for every country. Having the vaccine DOES NOT stop you from passing it on and HAVING the virus. It just prevents YOU from being ill, hence the necessity for quarantine still. Simple really.
foreigners cannot own land therefore you cannot buy a house and if your company bought it that has to have a Thai partner with 51% shares, so how can you? Or do you mean your wife?
residency cost about 200K and only about 100 applicants a year are excepted, the process takes about 18 months and you have to take a Thai language test etc.