I think you have or had 4 separate problems.

1) The diagnostic light code would tell you if the evaporative emission control is leaking and that should be addressed specfically. Did the light stay off or return after the work was done?

2) The 850 does not have a pcv valve as such - on turbos or non-turbos there are rebreathing (crankcase vent) lines with different arrangements and orifices. These need to be kept clean to prevent engine oil seals from leaking or blowing out (can be $$$). A clogged rebreathing system would not give you a diagnostic light as its function is not monitored - the light meant something else was/is wrong.

3) Leaks at the radiator for the engine oil and/or auto trans oil coolers do occur (especially after nearly 10 years) and this is probably independent of the other problems (though a clogged rebreathing system could make it worse). How bad is the leak?

4) A fast idle at cold start is usually normal - how fast and how long? Cars I've had idle at 1500-1800 rpm for half a minute or more when started cold. Then they settle down. If the car idles fast for a long time with no other defects in performance and no check engine light, maybe the throttle plate, throttle position sensor, idle air motor, or linkage are dirty or sticking. This may or may not trigger a diagnostic code.