if you have coolant in your oil your lim gaskets are bad or the upper intake as well if your N/A. change them asap if thats the case.
its almost impossible to get oil in the coolant. major head gasket failure maybe would do it but not likely.
trans can dump tranny fluid in the coolant and also get coolant in the trans, because of the tranny cooler that's built into the radiator.
the ticking sounds. start the engine, valve cover off while its running grab each rocker, make sure its tight feeling. while doing this the noise may stop or seem muffled.
you can also spin each push rod, and tell if its bent by doing so. sometimes they spin easier when the cars running. sometimes no problem when off, just depends on how hard its being pushed on by the cam/lifters and rocker arms.
