[hauget]

"Can anyone suggest a few problems with max completion times for each that will let me know for sure?"

I think how "good" you are at something is a very subjective thing... That said, have you tried programming competitions and projects like HackerRank, TopCoder, the ACM-ICPC, and Google's Code Jam?

PS: if money is not your main motivation, I'd worry more about finding interesting questions/problems that you enjoy solving rather than questioning your aptitude for it.