in reply to first two words-pattern matching

^(\w\s+\w\s) That matches a single character folowed by one or more spaces, folowed by another single character, folowed by one space.

What you probably want is something along the lines of

^(\w+\s+\w+\b)
Note that I removed the final space from your match by replacing it with \b - I assume you don't really need that final space.