Well, i re-read the section in the FRCS book about Circle Magic. I think I understand it a bit better now, but let me run through some examples, and ask some questions where i don't know how it'd work.
A 5th level red wizard/5th level wizard, Bernard, begins a circle. Assisting Bernard are 5 4th level red wizards/5th level wizards. Each of the assistants cast a 5th level spell into the spell pool, giving the pool 20 levels. Can Bernard also cast a spell into the pool to add to those 20 levels? If Bernard uses three of those levels to maximize his Cone of Cold spell, but he has two cone of cold spells, does it maximize one of them or both? He has 17 remaining levels (assuming that he doesn't add his own). Can he then choose, throughout the day, to use those levels whenever he wants? If he chooses to use them to increase his spell-check level, is that just effective for one spell, or is it for all his spells that day? If he casted that cone of cold, increasing his caster level to 20th (max).. and then tried to counterspell an opponents spell, and added 7 levels to his dispell magic caster check.. does that mean his pool is used up for the day?
Can Bernard form another circle, an hour after he did the first one, and absorb more levels from the same wizards, or different ones?
Can someone adding to a spell pool use a magic item, which grants a metamagic feat 1/day let's say, to increase the spell level of their spell? For example, Raymi has a staff that let's her maximize one spell per day. Can she maximize her cone of cold spell, and add 8 levels to the spell pool that way?