1. I got a wyeast pack and split it into two 2-liter flasks with DME wort for 24hours, shaking somewhat often. I figured I needed 400b cells. Do you think that came close? This should be fine. If you didn't achieve the 400b population, then fermentation will just be a little slow getting started.
2. With a recirculating mash I wasn't sure if I needed to stir it at all. I stirred it for a few minutes at the beginning then stopped. Is that acceptable?I can't really advise on recirculating systems (I use tiered), but I would think that as long as the grain is well soaked with the strike and you didn't have a stuck sparge, then it was fine.
3. Our mash cooked for longer than expected because we had trouble getting the pump to prime (actually a valve was closed instead of open). We wanted 60min but probably went 90. Is this ok?This depends on temps and rests. What did your mash schedule look like? Depending on the temperature, it would affect your starch/sugar conversion (possibly affecting body and alcohol levels), but that's not the end of the world. You will still make good beer.
4. Sparge went fast because I thought the fly sparge arm should spin and the water should stay above the grain. Is it fine if the sparge arm just slowly drips? it seems pointless for it to spin if the water is above the grain. Also, i've read a sparge should be much longer maybe 45-60min.The purpose of the sparge is to get every last drop of sugar out of your grain. Best practice is to have a spinning drip that keeps water about an inch above the grain bed, until the wort leaving the mash tun is clear. Everything else is boil off or watering down your beer IMO.
5. Boil went ok. We didn't have any problems with boil over because we had 8 gallons in a 26 gallon pot. Is it fine to just let it foam like crazy if it's all staying in the pot?The only thing I can think of is if the boil is too hot you might burn wort at the bottom, and this could give some off flavors. I personally bring it to a boil and then lower the flame until I get a steady bubble but no foam.
6. We poured the wort out of the pot through a screened funnel into the carboy. It's splashed and foamed. Do you think it's aerated enough? Aeration is a hot topic. How much air is enough? I've made great beer just shaking the fermenter. As long as the wort is room temperature (avoid hot side aeration) it's to your preference.
7. Moved to a second fermentation after a week. What ways do you use to determine when this should be done? Should it be fully fermented when we do this?This is another debated topic. I'm on the side that leaving it in the primary for 3 weeks (but no longer) provides benefits of a cleaner, more mature tasting beer. The idea, put simply, is that the yeast will actually clean up after itself, ridding what some of us identify as off flavors. Ultimately if you leave it in the secondary long enough for it to completely ferment out, you're fine.
Hope that helps. Perhaps some of the RMS guru's will chime in here for you. =)