RE: broadhead vs. field point flight
Well there is a lot of truthto what 360 says, A well tuned bow will shoot a broadhead very good. But to say they will all fly like fieldpoints is a bit misleading. You'll need to practice and see which heads fly well for you.
Generally the smaller the diameter of the head the better it will fly, but you sacrifice cutting diameter. So you want to find the middle ground. Is durability important? Price? Replaceable blades? Ease of assembly? There are plenty of great heads out there both fixed and expandable. Have your bow well tuned and find what you like best. Muzzy, G5's, Slicktricks...there is a plethra of good choices available.