Hi Stephanie, welcome to the forum. Lot's of great information and very knowledgeable people here, don't be afraid to ask questions.
I have a Brinkmann vertical offset, which is going to work a little different than yours. Biggest thing I've found is to use a chimney to get charcoal burning and good and hot before you add it to the firebox, and give your smoker a chance to heat up good before you add food to it. Watch the smoke, learn the difference between cool, white smoke (not good) and hot, thin, blue smoke (good). Never put cold charcoal or wood directly on the fire (see white smoke above). To answer some of your questions:
1) depends, if I'm doing a butt for pulling I load it up, because it's going to be a long burn. For chicken I'll use one chimney. For ribs I'll start with a chimney, then switch to wood just as I need it.
3) Have never used mine to cook in the firebox
4) Take some time to learn your smoker. I thought I would get it right, right from the start, and the first few things I made were just barely edible. Have patience and keep at it, my family says everything I cook now is so much better than the first things I did, and actually ask for stuff now. Temperature and smoke control will be the biggest part of your success, and are the hardest to learn, but have patience and stick with it. Relax, and have fun!