If you do it before July 1, then yes, if you reside in Thailand for the remainder of the year then technically that is money remitted into Thailand and could be taxable. Best to make your move here July 1 or after to avoid the 1st year of remittance.
Not everyone typecasts people. But fact is that many relationships between Thais and foreigners are in fact transactional. That doesn't take away from the relationship, it is just a cultural difference and acceptance and it doesn't apply to all. It's just one of many forms intercultural relationships can take.
don't bother with an agent. Process is easy and straight forward. If you use their money, your illegal from the start. Don't support further corruption.