get yourself a dash cam, nobody can deny what is playing on a video in front of them, you say you will get a local Thai to help with negotiations, just be aware some will add money for themselves during the negotiations, (a sort of undeclared commission) if someone has helped you, okay they deserve something in return, maybe a bit of money or a few beers, but in a land or house purchase they could add thousands on, being the middle man/woman and you wouldn't even know, many farangs think something is cheap, just because it's cheaper than there home country, when in fact it could be much more than the going rate.
Where are you in Thailand?? If it's rural nobody cares, just be prepared to pay for any damage if an accident is your fault, to many people commenting thinking it's the same rules as their home country.
Remember with the METV visa, if you do a border bounce just before the expiry use by date, you will get stamped in for another 60 days, that you can extend once at your local immigration office, doing it that way you can get 8 to 9 months out of that visa.
I use an insurance broker that has an office in Pattaya, I purchased accident and critical illness cover, I think they were two separate policies, at a cost of between ฿6000 and ฿7000 each for a 12 month policy, I don't have any links from the messages I mentioned, because I always just delete them, but if you want the link to the insurance broker I use, I could DM the link to there website in a message, it is run by a British expat, you could e-mail them for a quote, or even better depending on your location, just go to there office for a chat so you know who your dealing with.
Generally speaking, you could just take out a good accident and critical illness cover, and self insure for everything else, it's not expensive to treat minor illnesses, a bad accident or a critical illness are the two things that could potentially cost you a lot of money, I get messages everyday from AXA and AIA saying polices start from ฿9 a day.