Chevrolet - 1500 :: 1998 - Brakes Malfunction / Truck Not Starting Smoothly

I have a 1998 Chevy K1500 4x4 which is experiencing issues on two fronts: brakes and general operation.

For the brakes, over the last couple years, we have replaced just about every part of the system, including - master cylinder - calipers - brake lines. In addition, in the last week, I worked with a local mechanic to bleed the lines and he turned the rotors as well. The result is that while the truck does stop, the pedal height is still really high and feels like there's no pressure until the pedal's nearly to the floor. I get the feeling that if I needed to stop abruptly or at a higher speed than 35mph, I wouldn't be able to. I'm not sure what needs to happen next.

As to the general operation: the first time I start the truck on any given day, it fires up and runs smoothly. If I take it across town, however, and put it in the park, it gasps, sputters, and dies. It is then very difficult to get the vehicle to start again--usually, I have to push the gas pedal all the way to the floor and grind the starter until the engine turns over. After that, I have to keep my foot on the accelerator for 15-30 seconds at around 3000 RPM as the truck shudders and lurches, until it smooths out. Once I put it into drive or reverse, however, it dies, unless I am quick to push the accelerator again. Until recently, the truck had only been driven four times in the last two years or so. So far, I have: - replaced the air filter - added fresh gas (to the old) - added an engine treatment (Sea-Foam) Everything I have done is stuff that needs to be taken care of anyway, and I want to take care of all the little things before I take it to a dealership to have a full diagnostic run on it. I also plan to have an oil change done on it this week.