This isn't a common visa, at all, so your best bet would be to call them up. However...
1. In Thailand, "Work" basically is any activity that generates an output. This can range from being a programmer working online, changing oil on your motorcycle, or working with elephants. All work requires a work permit. It appears this visa will let you do any non-forbidden work (i.e. prostitution, working as a shop clerk, manual labor, etc. See
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for the list)
2. From my readings on the requirements, the answer is no, you do not *NEED* a job.
3. From my reading on the requirement, the answer is no, but you need to show proof of funds that you can purchase a ticket back home.
4. I'm not sure at all how long it takes. I'm assuming maybe 1 - 1.5 months if that is what it says.
About the Multiple Entry Tourist Visa:
1. It does get processed a lot faster, generally 1 to 2 business days.
2. It allows you to stay in the country for up to 9 months.
3. you must leave the country every 90 days.
4. You can not work, or volunteer on the visa.