Down here in my state Victoria, Australia..
1) Does your state have an inspection program?
yes
2) Is it voluntary or mandatory registration?
voluntary but you are supposed to be licensed and if you send a honey sample each year it is tested for free and you get a reduction on your license fee. I pay 15 bucks a year for 2 hives instead of 18 bucks.
3) Do they do both commercial and hobbyist inspections?
yes, you can ring up and they will come out and have a look at your one hive in the backyard, otherwise they will never visit a hobby keeper. Commercial operators are inspected more thoroughly and often.
4) What are the fees? Are they a one time fee or per inspection, per yard, or fee based on number of hives in the operation?
Annual fee, based on the number of hives up to 200 or so, then you fall into a category that I am not privy too. 1 or 2 hives, 15 bucks then something like a sliding scale, each additional hive after 50 or so, 40 cents each.
5) Do they inspect every year, every other year, or only when requested?
You send a 100ml or so plastic sample jar to the govt dept every year, they send it to you with a pre paid pack to put it in, photo instructions on exactly what they want to see in the jar. Goes straight to the lab, a private company. About a month later you get back the results. If your sample is positive, they would come around and make sure it was treated or destroyed if you had AHB or Varroa etc., otherwise, a hobbyist wouldnt see an inspector in a life time unless they called one. Commercial operators would have good relationships with the dept of agriculture, have to submit reports on where hives are and are going etc, they would face regular random checks and their processing plants would be checked by a few agencies as would their honey. We all rely on them and customs to keep us free of pests and diseases. So theres no reason down here not to cooperate as much as possible.