Only one putting misinformation here is you. The DLT doesn't take tm30s, only immigration does. If you're a foreigner you need a certificate of residency, buyer or seller.
- Yes, you do physically sign the greenbook. Mines signed.
-whats the 2nd form you say needs to be filled out?
Depends on the vehicle. Only a few companies will insure motorbikes, and normally only big bikes. My buddy has a cbr650 I think he pays 12k baht a year for 1st class.
Personally, I always either leave my motorbikes in the Thai person's name I bought it from, or put it in a thai person's name. Have the seller sign the greenbook, sign a copy of their ID card with phone number, and fill out the sellers side of the transfer of ownership form. Leave the buyer side blank.
- you have to buy the mandatory minimum insurance when you pay your yearly tax. Other than that, most motorbikes does have 2nd or 1st class insurance.