If you transfer from your bank in your home country in your home countries currency then you will get the telex transfer rate which is good. Banks such as kasikorn record this as an international transfer and it will be coded as such in an entry when you update your bank book. So your bank book is your evidence of international transfer. This is with kasikorn don't know about other
You'll need 10 million baht invested in a qualifying condo development. You can then apply for an investment visa as opposed to a retirement visa which would negate the need for the 65k/month or 800k in the bank. You'll need to show that the 10 million was brought into Thailand from abroad