1. Primary until you hit FG. "Secondary" on this board is often confused with what pro brewers call "bright tanks" which allow for more time for sediment, protein, and yeast to drop out and create a "pretty" beer. A true Secondary ferment is when you add more sugars/fruit/adjuncts after your primary fermentation has completed.
2. Best advice is to invest in an oxygen system. I have the one from Williams Brewing. If not, splash it into the fermentor and shake the bucket a bunch and just deal with a sub-optimal O2 saturation... nothing you can do about it w/o an aeration stone.
3. What is your batch size? Assuming 5 gallons, and your bucket being 6 or 6.5... you'll need a blowoff tube with almost 99% certainty.
4. unsolicited advice: Use Mr. Malty (www.mrmalty.com
) to pitch the appropriate amount of yeast. Ferment the beer at the lower end of the range noted by the manufacturer. Invest in an aeration system (O2, sterile pump, etc.). Look into putting together a "swamp cooler", big beers generate lots of internal heat when the yeast gets going, it could be 10F over ambient.