A work permit isn't a given and I imagine has to be applied for in person rather than in advance. Typically you'll get one if opening a business and offering employment opportunities to Belizeans. A lot harder if working for someone. Residency is applied after living in Belize a year, proven with all the correct stamps. There is a maximum amount of days in the year prior to residency you can leave Belize for. Something like 15 days.