You can get a job in a company that requires english speakers. But if you just want a normal, everyday job, then it would be extermely difficult.
Ask yourself this:
What kind of special skills do I have?
Can this kind of skill be taken to any country?
Does a lot of people in Thailand also have this skill?
The idea is to have a skill that is portable, and not a lot of people in Thailand have. Example, you could have a skill that others here have, but you also speak English, which makes you stand out more.
And of course, regardless of what reason you come to Thailand for, you should always try to learn the Thai language.