Certainly would seem OK with a SMV Triangle.
Regarding insurance, I don't think you can (nor would you want to) carry an automotive-style insurance on your tractor. I recently had this feature clarified by my agent. If it is stolen off my property, homeowners. If I wreck it on my property, I'm hosed. If I'm trailering it and get in a wreck, I'm hosed.
When driving it on the road, I would think you'd be treated similar to a bicycle or moped. You don't need a license or insurance to run either, yet you can conceivably cause damage and it be your fault. I figure it would go under the "uninsured motorist" side of the insured vehicles ledger, if that type of damage was inflicted.
There is another option for YOUR safety in case your tractor is damaged on or off your property...there is a type of personal property insurance you can get that would take care of you if, for example, a tree fell on your tractor. Or if you lose the tractor off your trailer while in transport. But I don't think the intent of this type of insurance is to cover the other guy's loss if you spear his Honda Accord with your FEL.
That's how I'd figure it.