[1995lumina]

I have a few question about my 1995 chevy lumina it has 190,000 miles nothings been change on it be sides oil changes, tune ups ,transmission oil and breaks. nothing else. my 1st question when its cold out you can here the water pump make a scraping noise and also when the motor is cold it makes a ticking noise i was wondering what was wrong with that and if it was the some thing or two different things. next when i am on the highway going 45 to 50 the car jumps but after that it stops but in the drive that saves gas on the high ways it really jumps and when you take you foot off the gas the car jumps to and the service engine soon light comes on but when yuo shut the car of the light goes of until u drive 40 and drop speed . last when i put my foot on the gas like all the way down takein off from a stop light some times the car cuts out so i was wondering what was wrong . please help