Check the fuse #3, and if it's OK, then you will need a wiring diagram to diagnose the circuit for the running lights.
Look on the bottom of the radiator, there may be one there, or there may be one on the engine block. You can also remove the bottom hose from the radiator for a few seconds to allow some of the water to drain out.
Your Blazer didn't come with a cabin air filter!
I don't have the maintenance chart for the 2007 Sebring, but if you look at the parts that are actually replaced at the 60k service, that will give you a good idea as to what is most important, as well as an inspection of the brakes, belts, hoses etc. Your owners manual should have the maintenance chart.
The torque for your flywheel is 80 Nm (59 ft. lbs.). Make sure you tighten them in a star pattern. Here is an image that will help! Copy and paste this link! www.explorerforum.com/photopost/data/500/lugTorque.jpg
It's very likely that the head gasket is your problem. These gaskets often leak if the engine has been overheated, but can occur on an engine with high mileage too. The next step is to have a shop remove the head(s) and inspect the head gaskets.
Many vehicles have a shift lock mechanism that is "un-locked" when you depress the brake pedal, is it possible it is related to this feature?
Check the fuse for the brake lights first, then make sure the bulbs are OK. Then you should look at the brake light switch, some are adjustable, and will not work correctly if out of adjustment. The switch may also be defective. There are other possibilities but these are a good place to start!
This code normally points to a faulty transmission control module, but this is an expensive part and you should have an experienced Dodge technician diagnose the problem first.
If you smell gasoline, have it checked out yesterday! A fuel leak can cause a fire and a burned up vehicle may be the least of your problems, so don't procrastinate on this!