I would start with fuel pressure check see if you are getting proper pressure to the front of the car

-- if you are getting the correct pressure then you know the pump is working correctly.

--the hardly idle problem can be mult. problems IE bad IAC and a map sensor issue causing the car to run reall rich simulating a idle problem. As for the white smoke could also be fuel .

--another thing to check is to see if there isnt a problem with the feed line fro the pump to the line in the top of the bracket that holds the fuel pump sometimes i have seen the hose there spring a leak and not get enough pressure to the front of the ar thus poor idle and your running water sound.

-these are some of the things that i would check and fingured id give yea little of my 2 cents. hope this helps. good luck