#1 It's OK to start using someone else's rub at first but eventually you'll want to make your own rub to be called a real smoker. It's just like baking a cake with a boxed mix or making it from scratch.
#2 No and No. Just rub it and put it in the smoker and leave it there until it's time to take it out.
#3 Anywhere from 225 to 250. I cook at 225. The main theme here is low and slow, that's where the flavor and tenderness comes from.
#4 IMHO The final temp for a shoulder should be no less than 190, even 170 is pretty low. Some go as high as 200 or even a tad more. I say anywhere from 190 to 200 and you're golden.
Plan on a minimum of 1.5 hrs per pound but plan on longer or shorter by a large margin. The idea is to allow yourself plenty of time if you have a specific time to eat and have a cooler standing buy if the piece of meat decides it's done sooner. It's all in the piece of meat and how long it takes to get to the target temp. Something that you just can't predict and never will be able to reliability. Not if you're cooking it correctly anyway.
#5 Hickory. You can use a mix of say Oak or Apple with Hickory but from where I come from (the south were BBQ was invented, specially pulled pork) pork needs at least some hickory smoke to be done right.
#6 NO! Put the meat in the smoker and leave it alone to cook. Keep the lid closed, damn it. If you're looking you ain't cookin. The less you mess with it, the better it will be. Learn to have some patience and keep yer mitts off till it's time to pull it and eat it. If you want something to do, you can always use the time it's smoking to mix up the slaw and a finishing sauce or even better whip up a batch of hush puppies. If you're doing it right it should take almost all day or all night so you have pleaty of time to do the other stuff. If you can't do that then just sit on your hands unless you're adding fuel or wood. Mow the lawn, rake some leaves, watch a game, chase the old lady some or chase the neighbors old lady, change the oil in your car etc. but leave the meat alone to cook.