Regarding “regards” or “regard,” remember that the singular form of “regard” is proper in phrases such as “with regard to,” “in regard to,” and similar forms. This seems to be a loose rule these days, since it’s found incorrect so often—even in edited material—but if you’re looking for a straight right-and-wrong answer, there you go.
The plural form of “regards,” is correct in signatures and sign-offs such as “best regards” or “warmest regards.” It’s also the proper form when you’re “giving your regards”—to Broadway or anyone else.
This was a great question that came in recently, and I’ve appreciated the recent messages on grammar notes. If anyone has any other word usage quandries, let me know!