You’re right that getting a licence for substitute teaching is really simple. But in my opinion, it’s not worth it.
Based off your responses, I think you might want to check out [edit]. It’s not available in your state, but it’s available in a few of the states you listed. It’s a bit expensive, but the salary raise you’ll get for having a certificate will more than pay for the cost of the certificate process several times over.
This is the only program that will give you a certificate after taking two tests. It’s that simple. Note, however, that the tests are tricky. They’re not hard per se… But you definitely need to study. For example, I remember one question on the practice test asking “what is the best way to introduce a lesson on rectangles?” If you’re not familiar with modern education theory, you might be miffed that there could possibly be a “best” lesson intro on rectangles. But with enough reading and study, you can start to get the hang of what they’re looking for in terms of answers.
They will issue you a real teaching certificate which is recognized by the US Department of Education. It’s not a temporary certificate, substitute certificate, or a TEFL ccertificate. It certifies you to be a full-time subject teacher in the States. However, it’s frowned upon by almost every school in the States. I have a certificate from this program and US schools look at it as if I graduated from Hillbilly University. But Taiwanese schools don’t know this. It looks real official and even if they call the US department of education, they will confirm that is real. But since you said you won’t want to teach in the States, this would be a good option for you. Just be warned that if you end up loving teaching, coming back to the States to teach won’t be a real option.
EDIT: I deleted the name of the program because I don’t want word to get out that this is a Hillbilly certificate. I’ve used my certificate to get a job at a very competitive school in Taipei and I’d like to keep my certificate worth something! @TheGuy, I PM’d you the info.
If anyone else is interested, PM me.