Oz,
Not the first time this has happend to you and also is something that you have counseled others on.
In your heart you know the answers. Life is short as jackhammer says and anything that brings happiness into your life should embraced and enjoyed. There are always problems but the smile on your face that someone brings is always worth the bumps that inevitably come with the relationship.
Whether you take him with you to Thailand or just spend more time in Brazil , it will be worth it. The language problem can be overcome and only one of you has to be willing to meet the challenge in order to improve the communication.
As you have said you know many relationships that started out as paid encounters that have flourished for various periods of time. Maybe most eventually come to an end but so do most marriages. Life would not be very interesting if everyone stopped pursuing the ultimate love affair.
But you will need a bigger condo in Thailand , so this time please get something with a guest cottage for your friends.
Have fun and enjoy as I know you will!!!!