Learn English – What does “shoot somebody a smile” mean

Well, I bit the bullet and asked the guy what the heck he meant (imagine that). Turns out he was referring to the oft-quoted teach a man to fish proverb.

He also clarified that this is not a common expression, just an idiosyncratic reference he invented and uttered spontaneously.

From this list of slang usages...

Sweating - constantly after a girl or boy you want and making it extremely obvious.
(stop sweating her already damn)

I think I can safely say the usage isn't particularly common with this specific sense. But it's easy enough to see how it would arise from...

sweat
5. Informal a.) To work long and hard. b.) To suffer much, as for a misdeed.
6. Informal To fret or worry.
10. Informal To fret or worry about: Don't sweat the details.