I also shot RAW. I took about 1,800 shots, which took me about 6 weeks to process (fitting in whenever I could find time).
Re: equipment, preparation is key. I got 2 16GB SDHC cards beforehand and had plenty of space on them. I have a battery grip and I use Lithium batteries, so I didn't need to stop to change batteries. I also brought an extra set of rechargeables for my Sigma 5300 flash, but didn't use it enough to need to change the batteries. Your mileage may vary, but, if you've only got one camera, you're going to want to limit the amount of time your camera is not ready.
Having a wrangler is definitely a good idea. You will drive yourself nuts if you have to round up everyone for each shot.
Definitely shoot with equipment that you know. The wedding and reception I shot were in the same location in the middle of a sunny summer day, but there were 6 different lighting scenarios in the chape alone. On top of that, we paused to do shoot the various combinations of family and married couple together in a space that was very different (dark foreground, very bright background); shot the bride and groom under bright sunlight; shot the wedding party under deep shade; shot the cake cutting in a well-lighted yellowish room, then shot the reception in a big conference room with lots of very bright windows. You may not run into the as many different challenges, but don't bet on not. You may be better at handling different lighting than I am. But it helps to know your camera and how to handle different lighting going in. So, even if you end up stuck with what you have, you're far better off know what you have and knowing it well than having better stuff you don't know.
Remember that you're not just there for the couple. The bride and groom may want avant garde shots, but the parents will be disappointed if you don't get the standard shots.
I agree that it's very important to be assertive, but equally important to not be too intrusive. After all, the day is about them, not you. Do make sure you get enough food and water. Nobody likes having their day ruined by a photographer who passed out from dehydration>