Constant speed props: These seem to garner a lot of misunderstanding. The prop tables in the air file and the basic parameters in the cfg file determine how the prop behaves. The cfg file entries set the limits more or less, entries controll the RPM range, typically 1200-1400 at the low end to 2700-3000 RPM as a max for most WWII piston engines. The max and min blade angles can be specified, which typically run something like 15-65 degrees with a feather Angle also specified if it is a feathering prop.
The prop will change it's pitch to maintain the load on the engine such as to keep a constant RPM without regard to the HP being developed. The MP value is the best power setting instrument, however a matching RPM should be set for best efficency. High RPM wears out the engine and is not fuel efficent. For cruise a lowish RPM will be set, with a matching moderate MP value. For takeoff usually max RPM is set and when climb power is made, first the MP will be reduced, then the RPM. The idea is to avoid having too much MP in a low RPM situation, which can result in cylinders flying out of the cowling etc.
CHT is not perfectly modeled in the FS series and seems to be much related to RPM and not as much to MP.
Increasing power, move RPM up first, then MP. For combat select either takeoff power (full RPM and rated mil MP) or max continouous power, which may have a slightly lower rpm and MP values. In a tight situation, WEP is available in some aircraft for a short time.
Good luck! T