I bet Yooper responds soon to your questions. I'll give a swag too. BTW, our first batch from last June is getting pretty tasty. Bringing a 1.5L bottle up to the lake for Memorial. If I'm out picking rhubarb for our 2013 batch, its time to start consuming!
1) Lees are the yeast and fruit particulate that drops out at the bottom of your fermenter.
2) Tannin gives some extra flavors that might be lacking and helps protect it during aging. I would stick with it, but have no experience in this recipe without.
3) Camden is just used in the beginning prior to yeast pitch to control any wild yeasts in the fruit from reproducing. It dissapates over time so that the yeast you pitch are the primary fermenters. Camden added after fermentation is over is there to prevent oxidation and limit yeast reproduction to shut it down.
4 )I don't know much about the Youngs Super Yeast Compound, but from what I gather its usually used in really high alcohol ciders/wines/distilling. If it were me, I'd try and get some of the more commonly used wine yeasts like Montrachet.