1) Is Bitcoin-Denominated Debt Enforceable?
In other words, say I lend someone X BTC (unsecured), and get them to sign a promissory note for the X BTC loan, etc... etc... Now, assume they didn't pay me back. Could I theoretically pursue them for this debt, and potentially take them to court? If so, would I receive only the USD value of BTC lent, or is there a way of writing a contract such that they would be obligated to provide me with the actual X BTC, no matter how much it is worth in USD terms, now?
Yes, there is. I've dealt with these agreements before. It's not as simple as just substituting BTC for USD in the text of the agreement, but it isn't impossible either.
So if this sort of agreement is not in place, depending again on local law, legal tender laws may apply to debt repayment and you get the local fiat?
I may also seek a drafting, when it becomes a concern that warrants this.
Also check your state's maximum personal loan interest rate.
Yes and this is a changing target in many of them.