A have a few questions concerning the hay bale ceremony only seating

1. We are getting 50 hay bales. We are figuring two people per hay bale. But we are also hoping families with small kids will sit three people to a bale. So question is how many programs should we put on each hay bale 1, 2 or 3?
2. We are also going to have one row of chairs behind the last row of hay or maybe two at the end of each row on the outside. Do you think I should make little reserved signs for (??? I don't even know what to call them) people unable to sit on hay bales? So I guess two questions. Should there be signs? And what should the sign say?
3. Last question. Can I put the canvas on the top and only a couple inches hanging over. This will save a huge amount of money. Or is it not the right place to cut? A lot of the hay bale seating I have seen online has cover on top only.
Thanks sooo much! Have I told you knotties I love you!!! LOL You all help out soo much. I don't know how I would get all these little things figure out without you all

You are much appreciated!!