1). Definately... if you are going to be hunting out of one.
2). You MUST practice with broadheads before heading into the woods.
3). If you are bowhunting to shoot a deer you owe it to the animal to be accurate and deadly. If your chosen broadheads don't fly correctly, you may need some fine tuning (or possibly to switch heads). There is no reason why your accuracy with BH and field points can't be top notch even with an older bow. Do you spin test once the BH's are put on? If not, you should. There are lots of variables to consider.