I could write a small novel re education here! If you have no experience you'll have your work cut out and may find it frustrating or disappointing. Also remember that volunteer teachers are a dime a dozen here, and not all of them are particularly effective. The longer you're here the more you get a sense of what's needed, what works, what doesn't, what's helpful and what makes things worse despite good intentions.
As to the inspection, it was after around a week of staying there that the authorities turned up. To that point, given I'd been seen in town, and that Pyin U Lwin is a military town at that, it's not surprising that people were checking up on me. Since I was working with small children with no security vetting, I'm glad for the community's sake that they were checking up on me.
Business and meditation visas require 'sponsors' - a businessman or sayadaw. They are taking responsibility for you during your time in the country and it's not just a formality. Therefore, you will be asking the sayadaw to effectively vouch for you whilst you are in the country and on your visa. If you want a visa that has one set of conditions to cover for you doing things out of those conditions, think about what you're effectively asking your sponsor to do. If you do anything the authorities don't like, it will (not may) come back to the sayadaw and may affect his ability to sponsor business visas in future. It won't be obvious, but people watch and talk/report here, especially about foreigners. If the sayadaw is happy for this then that's their decision. Some may regularly 'vouch' for teachers on meditation visas provided they don't spend too much time out of the monastery. Others may not, depends on their prior experience, standing with the authorities, type of monastery etc.
My personal view is that the immigration laws should be complied with and not circumvented. It's for this reason that I'm registering at my new apartment, even though it is a horrendously time-consuming, bureaucratic and expensive process (imagine trying to register with a government agency that has a hierarchy at different offices across the city, you must notify each stage of the hierarchy, they all keep separate paper records and none of them talk to each other). I'm too invested here now, financially, emotionally and resource-wise, to risk being thrown out or having trouble caused to me or those around me.
It's not clear cut, sadly. All depends! I veer towards the cautious end. Others do all sorts on tourist, meditation and business visas and are fine. My risk assessment may be different to yours.
As to flights, I don't know whether there are direct flights to Mandalay from KL yet? There are from BKK. I prefer KL to BKK anyway so would recommend spending your time there before Myanmar.
No experience on getting meditation visas. My plan to do a long retreat at Panditarama is permanently shelved and I'm busy as anything here now (it's strange, as soon as you stop being a tourist/dhamma bum here and start working you get very busy very quickly). Want to do some more volunteer stuff when things calm down though, or even a day retreat (since I can't stay overnight).