One point on the bad shots - It's not if you get a flyer. You should go back to the bale if your execution is in any way less than the standard that you established on the bale. The shot may be a perfect bullseye, but if the execution wasn't good, then it's back to the bale.
This can take a long time. I heard a rumor that Rod spent about a year and a half getting back to the distances he shoots in competition. But he ended up being one of the best archers in the world.
If the year & a half is wrong, I hope Rod will correct me.
This program isn't for everybody. It's boring, it's tedious and it takes a lot of self discipline. You have to decide how good you want to shoot and what price you are willing to pay. However, if you HONESTLY follow it, you will be an excellent archer who can put an arrow exactly where you want every time. IMHO it's definitely worth it to get that feeling.
Number of arrows per session - As many as you want or have time for. You should do all of the drills that Rod showed you in every session, but sometimes you don't have time or are just not up for a lot of arrows. Generally the more arrows the better, but there is a point of diminishing returns. I try to shoot at least 40 - 50 arrows, but sometimes these old shoulders have to stop short of that.
When you are shooting the bale, don't group. Spread your arrows around so you don't damage them. But don't pay any attention to where they are landing. The bale is just there to catch the arrows. It would be better if we could shoot without arrows, but of course that would damage our bows. The less attention you pay to where your arrows land, the more attention that you are paying to your form.
If you meant the bridge at 5 yards, remember that the whole target is the bullseye. If you find yourself grouping, it may be better to shoot one arrow at a time. Arrows are expensive, you don't want to destroy them.
Hope this helps,
Allen