Doublegun,
It sounds like you are on the right track. Shooting a traditional bow off the shelf without sights is not hard, shooting it consistently well is the challenge..
Don't let my above post discourage you, there are some amazing shots that can kill game across all distances. I have 100% confidence that you can become deadly accurate out to 30yds with traditional gear.... It will take a lot of work and dedication, but there are many, many hunters that do it year in and year out.
A good way to understand the potential of trad gear is to browse the IBO website and look at tournament results.... These are the best shooters in the world shooting in optimal conditions.
If you can hit the kill zone every shot out to 30yds you will win most tournaments and with a good sprinkling of 10's you will win all tournaments...
Consistency is often what seperates the elite from the rest of the group... There are tons of very good shooters that can shoot a round of 3-D and have 80+% good shots. However, it's that 20% that keeps them from being elite.... The elite archers rarely make a mistake, they are consistent on all shots....
The best advice I could give is to develop sound, repeatable form combined with a perfected aiming system...
Good luck and good shooting.