..."and has no sub output at all if fronts are selected as anything other that "small"-"...
Well, I've never run into that problem, but your rant is generally correct that bass management is a joke. That's why I don't deal with it. Set your front speakers as 'large', run a stereo pair of subs off of the second set of L&R pre outs, and connect a third sub to the LFE out. Don't use the crossovers in your source or pre/pro, but instead use the crossovers in your subs to adjust them to mate well with your main speakers. The only disadvantage of this setup is that you don't get the benefit of removing the very low frequency info from your main speakers. To do that, you can add an outboard active crossover to the mix (Incidentally, this is, I think, the best way to go if you don't have an extra set of pre outs.). You didn't mention home theater, but if you use your system for both, as I do, then select more musically inclined subs for the stereo pair and a more HT inclined (read: slam) sub for the LFE. After a little time spent with a sound meter to get it right, it works pretty well for me. Now if I can just find a decent, simple and cheap active crossover...
Hope that helps --->