If you have the 2.6 engine, it probably calls for Bosch COPPER plugs, NOT the platinum plugs that the Mcparts stores want to sell you. What plugs did you put in there? Look in your owners manual for the correct plug, I believe they should b H9DCO. However, spark plugs are not your problem.
Why are you turning the key 5-6 times? What happens when you try to start it normally after it stalls? By normally, I mean one key start lasting 10-15 seconds. Kinda sounds like a Crank position sensor has gone bad. Do you have a lot of oil leakage at the back of the engine?