It's a formal way of expressing regards, usually used in the beginning of formal "inter-departmental, ministerial, etc." letters. Extend here means give.
office discipline
Both "as regards" and "in regards to" are considered correct phrases. However, "in regards to" is more commonly used in informal communication, and "as regards" is more commonly used in formal writing.
Regards, Kind regards, Best regards.
Regards
Regards was created in 1932.
kind regards
Kindest Regards
Yes
No it shouldn't be capitalized.
Only best gets capitalized. It should be--- Best regards.
No a comma is not needed after regards.
yes Kind Regards, Hollie