1. There is no minimum wage for foreign teachers here in Thailand. However, as a Westerner, you will need at least 25,000 per month to cover life's daily essentials, especially if the employer does not offer free accommodation.
There is part-time work and full time work available here ion Thailand. Depending on the quality of the school or high-street or back-alley language institute, remuneration can be anything from 250 baht to 1,000 baht per hour. Full time jobs are generally based on about 22 contact hours per week (actual teaching time), however, most mainstream schools require their teachers to remain on the campus all day Mon - Fri, while part-time work and the work offered by language institutes is concentrated mainly in the evenings and at weekends and you can do what you like between lessons.
2. Some schools in Thailand might deduct the cost of the work permit from your salary. Some schools will deduct the cost of the work permit from your salary and refund it on successful completion of your contract. Many schools offer free accommodation, but again, the quality varies widely and there may occasionally be conditions attached that some Western occupants may find restrictive (such as, for example, no booze, no visitors, regular room inspections, etc.). Some schools (especially universities) may offer a tax-free accommodation allowance.