for clarity, were you entering on an actual tourist visa/evisa that you bought from a consulate, or via visa exempt entry where you just show up without buying a visa first? Many people don't know the difference and use the wrong terminology.
A 6 month multiple entry tourist visa would grant 60 day stays (each extendable once for 30 more days), so you'd have to extend once, leave and reenter, then extend once more, to get 6 months. You can even leave and reenter a second time near the end of the visa's expiration date and repeat the cycle, granting you 9 months worth of stays out of that visa. Of course, every entry, even with a valid visa, is always at the discretion of the immigration officer.
IDPs never require any training anywhere in the world. IDPs are simply a translation of your home licence into multiple languages as governed by international conventions between countries accepting IDPs. The IDP isn't a drivers licence, which is why you must carry it together with your home country's drivers licence to drive internationally.
that doesn't meet the OP's specifications as you must exit every 360 days, assuming you extend the 180 days for the additional 180 days allowed one time. Given the cost of that specific extension, many people choose to leave and come back at 180 days. The OP wants a visa where he doesn't have to leave for over 1 year.
the QR code is tied into your exact passport number, as the immigration officer will be able to see it on their screen as well, so you can't use a generic QR code or one not tied to your specific online submission.