Or is it more probable the dough was just to cold and stiff to reball and I should have let it come to room temp first. I just don't know how to tell if a dough is over developed or under developed so I guess my biggest question now is, how will I know? I have read several posts which state the key to big open airy holes, other than higher hydration, is not over developing the dough or you end up with a tight crumb bready pizza crust. I do not want a bready pizza, so how long should I be kneading? By hand or with a mixer? How can I tell when the dough is just right? Is it the look? Is it the feel? Is it just trial and error and will come with time and experience? It seems like for every post I look at I now have two or more questions. Maybe I'm just over thinking it!? Uggggg 
Cindy, I will try to answer your questions here but keep in mind this is just one guy's opinion. There is no problem reballing cold dough or room temp dough as long you don't over do it on the balling. There is no set # of turns you should when balling. It really depends on the dough. If the dough is slack then it will require more than 2 turns. If the dough is stiff, it may not need any reballing at all. Reballing builds strength into dough and should only be used if the dough requires it. Reballing is done by feel but it is pretty simple to understand once you get it. Go to youtube and look up a few videos on reballing. Generally speaking you don't want to form really tight balls, unless they are to go through extended fermentation. How tight the balls should be formed is a matter of preference and in time you will learn what is the appropriate feel to your dough to achieve your desired results.
As far as underdevelopment or overdevelopment of a dough is concern, it is important to look at the consequences of each. If you underdevelop a dough, you won't get that open airy crumb. Instead you will get a more flat rimmed and not so airy crumb. If you over develop a dough, you will get an open airy crumb but as the pizza cools, the crust will become very chewy. The overdeveloped dough will be hard to open and will be fairly elastic (think rubberband). As you open up the dough or stretch it bigger, it will have a tendency to spring back like a rubber band. A little spring is good, too much is not. On the opposite end, if you have an underdeveloped dough, it will be too extensible. Meaning it will open almost too easily, be prone to tears, and just plain a PITA to work with. The dough may feel sticky to the touch.
As you make more dough and get more practice, and continue to read, you will learn what an overdeveloped or underdeveloped dough looks like or how each behaves. What Scott was talking about earlier is not only just overdeveloping a dough but extreme overdevelopement to where the dough will fall apart. Scott If I misunderstood you, please correct me. Cindy I don't believe that is what happened to your dough as 6min of mixing can not do that to a dough. Even a dry dough. What likely happened is either underdevelopment or even likier is that you overballed the dough thus tearing it and breaking the gluten strands.
If you want an open and airy crumb, one trick to doing it is to do a minimal mix in the mixer to bring the ingredients together (around 3min on the lowest speed). Then allow the dough to sit covered for 10-15min. At this point you will develop the gluten by hand by doing stretch and folds to the dough. Youtube this if you don't know what it means. Give the dough another 15m rest and repeat. You will do 2-3 or more cycles of this depending on how much strength you want to build into the dough or how wet (or weak) your dough is. You may or may not need to reball down the road depending on the temp of fermentation (cold vs. cool vs room temps) and how long you ferment for. Generally speaking the longer you ferment, the dough has a tendency to become weaker and release some moisture. This is where limited and gentle reballing can rebuild the strength of the dough.
How can you tell if the dough is just right? Well just right means different things to different people, but this is where experimentation comes in. Get a notebook and keep detail notes of every bake. For each new bake, you can safely introduce 1-2 new unrelated variables (no more) and see if you can see the difference. I usually do experiments with extremes. For example if I'm experimenting with hydration, I might try a 10% difference. I'll note how each dough feels and handles during initial mix, folding, fermentation, how they feel when they are divided and balled, how they proof up, how they bake up, and the end taste and texture. You can then get a good idea on where you want to be.
This is the only way to learn how to make pizza. It's not by recipes or not by what "the experts" tell you. Recipes and expert opinions can only guide you or put you on the path but it won't get you there. In time, your hard work will pay off.
Good luck,
Chau