I think you'll get a lot of answers to these common problems on
www.chevytruckworld.com. The forums there are great, and a number of folks have specifically enountered those issues. Some random thoughts...
Piston slap. It sounds horrible, but GM's position seems valid. I have yet to hear a vortec engine that DOESN'T have the problem. Unless you're using an excessive amount of oil, or hearing the slap at times other than a cold start, I'd recommend just turning up the radio.
Fuel pump. I'm not overly familiar with this one, but from what I've heard these pumps don't fail with any more regularity than those on other vehicles. The real drag is whe the pump is located in the tank, which I don't think is the case on your vehicle.
E-brake. This one is an example of what appears to be a shoddy design - an afterthought when deciding to go with rear discs. I've heard it's one of the main reasons the General is going back to drums for '05. Not sure if that applies to SUV's as well as pickups.
I'm now on my third current-generation GM full size SUV, and have been very happy. Compared to the Toyotas we used to have I've been a bit disappointed with the number of warranty issues, but there has yet to be a concern that's left me stranded, or worse, made me lose confidence in the vehicle. Furthermore, value was a key consideration in each of the purchases. Power, comfort, and features all added up at a lower sales price than any of the other vehicles we looked at. Zero percent interest doesn't hurt either.
I hope that helps a little...
Take care,
Jerry