2005 Kia Sorento? Repair or maintenance needed on car

Recently went to the dealership where I purchased this car. It was for a routine oil change and check-up. I was also having a problem with the car 'stuttering' when the brakes were applied. This started after the last oil change and rotation of the tires. At any rate am now being told that the front rotor's need to be turned and in addition 1. Transmission needs to be flushed and new fluid replaced (fluid was light brown. No burnt smell) 2. Coolant needs to be flushed 3. Drive belts need to be replaced ( all three) due to small "cracks". 4. That I need 2 new tires @ 110 each. And last but not least that I needed new windshield wiper blades. (When I have used these they have been fine. All told the repairs they say I need would cost me around 850.00. I have owned this car for 4 months. It was purchased used from this dealership and had 29000 when purchased. I guess that I am wondering if a good dealership would have noticed these things before selling the car. Also was wondering if they are all necessary?
I had asked an earlier question about the rotor's was told that the cause of the rotors being 'warped' was due to driving the car and the rotors becoming heated and then driving through water that was colder.I think if this is true that every car in the US would have warped rotor's. A friend told me that it was probably caused by the lug nuts being put on too tight when the tires were rotated at the last checkup. What are your thought's Thanks Renata