5.1 bass management

I do agree with most of your analysis but you are suggesting an arrangement that is already a problem since there's no reason to use 100Hz on C and 60 on L/R unless the C is lacking. Phase problems will already exist. Using 100Hz for all is better but too high for me. Small, independant differential adjustments are useful if guided by measurement and careful listening.

I disagree, It's not a good idea to have multiple crossover points. Bass is not dedicated to the LFE. It is often common among all three front channels + LFE. The problem (aside the inherent phase issues) is summing a mono bass signal from the different crossover points. If your center channel is crossed over at 100 HZ and your mains are crossed at 60Hz then the bass from 60-100 will be 6db louder than the original level because the mains and the sub will both be voicing it. So, after the summing, the combined level has to be attenuated back to the original level. Good bye signal to noise ratio and hello phase irregularities.

It is useful to have independant control of crossover frequency for all 5 channels even if the speakers are identical since their response is greatly influenced by room placement.

Beside looking for a component I have some questions.
Is it preferred to have all speakers set at the same crossover? Most of the crossovers I have seen are two channel. Is it not important to be able to set the crossovers for the center and the surrounds? Thanks

That's about it. Although I remember a review in Sound & Vision magazine on one made,I believe, by M&K.