lovemole, there are so many different charts belonging to really good astrologers that probably there is no single "Aha!" kind of chart. I have read in different times and places that most professional astrologers have their moons in water signs, that 11 degrees Virgo is the "astrologer's degree", that asteroid Urania should be prominent, that no one should be an astrologer who can't calculate a chart by hand (wintersprite1's point, above), that astrologers should have expertise in clinical psychology, and so on. At this point, I think one just has to realize that there are many different kinds of astrologers, ranging from the traditional and academic, to the intuitive popular sort. So maybe the issue isn't, "Can you be an astrologer?" but "What sort would you become?"
Winterspite1's point is well taken, though, because most of the professional astrology association exams that offer solid credentials do require applicants to do the math by hand. I also agree with her that a chart gives a kind of roadmap, but it can't be read in a deterministic kind of way. [You know the astrologers who say, "Well actually you have all those 12th house planets, so this is why your life *****;" or worse yet, "This is why you're a rotten person." Phooy to that take on astrology, I say!]
I think the best way to tell if you'd be good as a pro astrologer is just to read as many charts as you can, on this and other forums. Read charts for your friends and family. Ask them to give you feedback. That way you will know if you have a knack for astrology. Maybe you're already doing this. If so, you don't need any particular chart placements to tell you how it is going.
The ruler of the 10th in the 6th house of work and service looks promising. Especially if it is well-aspected. Of course, I wouldn't ask you to post your chart if you don't wish to do so, but how scary can it be, relatively speaking? There aren't too many "vanilla" charts out there!