1 This should be future tense, as I've neither driven a car nor hired a motorcycle in Thailand (so far).
The electric motorcycle was in Myanmar. Mostly off road, but quite possibly illegal.
2 Checking what I can do in the UK, with my provisional entitlement:
"Car driving test passed before 1 February 2001
You can ride a moped (max 50cc) without L plates.
If you want to ride a motorcycle over 50cc and up to 125cc, you will need to take CBT.
Once you have a valid CBT certificate, you can ride a 125cc with L plates.
If you want to remove the L plates or ride a more powerful machine, you will need to take the relevant practical tests."
So I need a CBT certificate (Compulsory Basic Training) in order to legally ride a bike in the UK. I think there might be a 2 year limit on that.
Now, if I got that certificate, I'm legal to ride in the UK with L plates. I don't have it yet, but there are plenty of providers near me & I guess it could be done before the next trip. If it makes any difference.
The next question is once I can legally ride a bike in the UK, is this also legal in Thailand ?
ie What are Thai rules for overseas provisional licenses ?
I suspect this is going to fall somewhere between not properly defined anywhere and not legal. So no point in rushing out to get UK CBT before the next trip. [google is not helpful on this topic]
I also had a quick look at getting a Thai motorcycle license, however, that starts off with a "proof of residency" requirement. Also takes quite a few weeks.
I CAN legally ride a 50cc moped with my UK license, but a quick look on google doesn't show anyone renting such things out in Thailand.
So it looks like it may be advisable to stick with fully legal car hire, for short periods during the trip.