Depends on your speakers, but unless you have to, setting at 200Hz is usually way too high.
The LFE track is specced at 20-120Hz, but apparently most start to filter off after about 80Hz anyway!
In any case, the crossover setting sets the point at which bass is cut from the main channels and redirected to the subwoofer - it's not really relevant to the LFE (.1) channel, as that is always sent to the subwoofer once you select SUB=ON or YES
Your sub setting is correct (for starters). I'd set all speakers to small and the crossover to 80Hz to start with, and then try other settings in comparison (eg, you may find the 100Hz setting sounds a bit better, or turning the sub's xover down a bit helps etc etc).
200Hz is easily locatable in a room - the idea with a sub is that the bass should "appear" to be coming from the normal speakers, not the sub itself. As below about 80Hz bass essentially becomes non-directional (the actual frequency point at which this is true is arguable), you can't locate the source, and so your brain is tricked into thinking it's coming from the other sound sources - ie the main speakers!