1. State A buys out a patentee for a drug patent. What stops the state from setting a higher price for sales to consumers in other states/other countries. What stops the state from refusing to sell to others?
I doubt the state would "buy out" the patent owner. I'm assuming you mean a forced assignment. I would expect a more limited forced license to make, use, and/or sell infringing articles within the state. An assignment is more than necessary and would affect too many rights outside state A.
So, I don't think state A will interfere with other states/countries. However, a license to make, use, and/or sell within state A seriously undercuts the value of the patent overall. Some licensees are willing to pay for exclusivity and that exclusivity would be severely undercut.
2. State A buys out a patentee for a drug patent. Patent is deemed invalid by the court/board for various, typical reasons (inequitable conduct, interference, lack of enabling disclosure) or even a reexamination that narrowed or invalidated claims. Does the state get reimbursed?
I suspect state A (as a licensee, not an assignee) would be treated like any other licensee. I believe that means no reimbursment. However, as many taxpayers expect everything for free, I'd expect some "action" over that point. Unfortunately for the taxpayers, I believe the Constitution requires reasonable compensation -- in other words, compensation is not optional.
3. State A buys out a patentee for a drug patent. Drug requires an element that patentee has rights via a second patent. Therefore, to make or use the new drug requires that the state buy out more patents. Either that or the state will have to contract with patentee to make the drug, since I doubt the patentee will allow a third party to infringe on this second patent without some compensation.
I suspect the state will take as many mandatory licenses as it needs to get its needs met.
This raises an interesting notion (pointed out to me by a friend who does licensing work). Years ago, an article might have one, two, three patents covering it. A reasonable royalty was about 2-5% (of net, I think -- perhaps gross). Now, you might have many patents covering a single item. A complex item such as a car might have as many as 20,000 covering various aspects of it. As you can see, 2-5% times 20,000 doesn't add up. If the state were smart, they'd use the existence of many patents to ratchet down the royalties paid to each patent owner.
4. What if the drug is sufficiently novel or requires such specialized techniques that only the patentee can, within reason, make the drug at a cost required by the state? Will the state buy out the patentee and then pay them to make the drug, too?
That's a tougher question and I have no idea. Assuming a license rather than an assignment, one might expect that quantities of this drug would be floating around the marketplace and the state would be able to get its hands on some.
5. What if the drug cures the problem, but winds up killing everybody due to really bad side effects. Is the state sued? Is the manufacturer sued? Does the patentee get sued?
Everybody gets sued. I think the patent owner wins, though, and escapes liability.
These issues are possibly endless. Does this stop at drugs? Could the state buy out a patentee just to avoid a monopoly?
Again, I foresee licenses rather than assignments. Given what qualifies as an "urgent" matter in current eminent domain cases (merely increasing a tax base is currently being asserted as an urgency), I think a heavily discounted license on Microsoft software is next.
Regards.