You aren't the only one to get confused by the different amounts of preferments used. If you take a look at Replies ##60-63 at http://www.pizzamaking.com/forum/index.php/topic,986.60.html
, you will see what I mean. However, to summarize, pizzanapoletana (Marco) recommends 1-5% by weight of water
, not flour. Marco's preferment is rather stiff like a normal dough, and his preferment is used in small quantity, in an entirely room-temperature (65 degrees F, ideally) environment. When I modified Marco's basic recipe recently to make my last Caputo 00 dough leavened by a dough-like preferment, the amount of preferment came to about 1/2 teaspoon, that's all.
In other recipes have frequently used my preferment at around 20% by weight of flour, a number I got from fellow member Bakerboy who is a professional chef/pizza maker and, if I recall correctly, used around 20-25% "old dough" (or pate fermentee
--old or prefermented dough) in his dough recipe when he made pizzas professionally. Jeff's preferment is at around 40% by weight of flour. It is a batter-like preferment. At 40%, it falls within a range of around 30-50% that is typical of usage in bread making. Jeff also uses his preferment in a retarded fermentation situation.
The important things to keep in mind about preferment usage in doughs, some of which scott has already alluded to, is that the results you will achieve will depend principally on these factors: the amount, type (liquid, semi-liquid, dough-like) and maturity of the preferment, the temperature during fermentation, degree of hydration, and the amount of salt. Within this general framework, and all other things being equal, a lot of preferment will allow faster fermentation, and vice versa; the higher the temperature, the greater the rate of fermentation, and vice versa; the higher the hydration level, the greater the rate of fermentation, and vice versa; and the higher the salt level, the slower the rate of fermentation, and vice versa. All of these factors collectively determine the duration of the "window" of your dough, that is, the length of the period from when the dough comes off the hook to when the dough is ready to be shaped. My practice is to determine the length of the window I want to begin with and then adjust the different parameters as best I can to get me safely to the end of the window. If you can master these basic concepts and learn how to properly combine them in a given situation, you will have little difficulty in making good pizza dough. Since the preferment you use is central to all these factors, it is important of course to get to know the idiosyncrasies and behavior of your preferment well.
As far as the type of flour you use to replenish your starter, it doesn't really matter what type of flour you use. I started one of mine on Caputo 00 flour and now feed it with any other flour I have handy, but only flours that are unbleached and nonbromated. You sensed properly that you shouldn't re-ball a dough just before shaping. That reorients the relaxed and soft gluten strands and creates a jangled network. When that happens, the best approach is to let the dough relax for about an hour or so. You can shorten this time a bit by putting the dough in a slightly warmed oven.
I hope your next Lehmann dough fares better than the last and that you get your oven situation straightened out so that you can have a chance to actually eat and enjoy the fruits of your efforts.