"Treasury Form TD F 90-22.1", to be precise. Yes, one of my favourites...
1) "Financial Account.
A financial account includes, but is not limited to, a securities, brokerage, savings, demand, checking, deposit, time deposit, or other account maintained with a financial institution (or other person performing the services of a financial institution). A financial account also includes a commodity futures or options account, an insurance policy with a cash value (such as a whole life insurance policy), an annuity policy with a cash value, and shares in a mutual fund or similar pooled fund (i.e., a fund that is available to the general public with a regular net asset value determination and regular redemptions)."
Based on that, I'd say the only insurance policy you would need to include would be a "whole life" policy, not a term policy. Credit cards do not seem to fit any of the above--do you have a credit balance on your credit card? The value you report is the highest it has ever been during the past year, not the ending balance. This bit, which was not part of the Form when it was first introduced, requires you to review every monthly statement during the year (for each account--I have about a dozen in three foreign countries, sadly, only one of which has any money in it) to find the point at which the balance was the highest. What fun! Even more fun if you transfer money from one foreign account to another: you get to record that value for both accounts!
2) Well, unless there is a de minimus exemption, I'd say yes, it is interest earned during the year (but you will need to convert it into US$ using some rate specified somewhere)...
3) I would think so. Why would it be excludable? The whole point of the TDF Form is to make sure that US persons are fully taxed on their hidden offshore millions.
I'm not an accountant, but that's what I'd do...