2 months before ( 60 days) some immigration offices want it to stay in the bank for the under consideration period, others not. As soon as you get your one year extension you can get straight down the bookies and blow it ( exept there are no bookies in Thailand) Does not need to come from outside Thailand.
dunno. Immigration won't give you the visa without it though. For the one year extension it needs to be in the bank (Thai bank your name only) for min 2 months.