Matt,
Read this from
Blue Sky
You might be over-thinking this. Bass management is only applied in playback, and usually at home to compensate for small main speakers. If your mix room has bass management, then calibrate that before doing anything. Mix to your ears, but be aware of level issues for broadcast (all that's in stickys at the top of the forum page)
It can be really confusing how the Sub channel is dealt with during Dolby encode/decode (+10dB here, -10dB there), but if you follow the calibration steps from BlueSky, things will start to make sense. Here's how I've done it.
1 - Calibrate your room per the BlueSky instructions. The DUC also has speaker cal info.
2 - Calibrate your Bluray/DVD playback so it matches using a test disc.
I have a 5.1 PrePro that allows separate channel level adjustment and will decode everything I throw at it. Once you have it set, don't touch it, and patch it's analog outputs as directly as possible to your monitors. You should now have a usable reference to compare what your mixes are doing once they go to Bluray/DVD. If you have a Dolby Digital encoder, this can go real fast, instead of having to wait to receive a check disc.
Look around other parts of the BlueSky website, lots of good info 5.1 and LFE use.
Bottom line is... you really shouldn't have to make major changes to your mixing, just be aware of the level differences and calibrate your room accordingly.