Bi-amping XLR or RCA?

Hello friendly people,
I have 2 questions that are interrelated. So here is the background: I now own a set of Wharfedale Opus surround speakers (Opus 1 mains, center, and surrounds) that I am currently powering with my HK avr 340 (very underpowered, I know) I have a B&K 125.7 on the way. I am going to use the HK pre-outs to drive the BK for now.
1) I thought it would be fun to try bi-amping the mains with my two extra channels with something like this: and removing the first hi/lo filter in the speakers so the driver gets a pure lo-pass signal and then the mid/tweet crossover gets the rest above 700hz. I would like to hear opinions/advice on the efficacy of actively bi-amping this particular setup.
2) I can’t decide to whether to get the RCA or XLR version of the crossover. I assume my next upgrade will be a processor with XLR outs. So, my second question is: if my sources are not balanced will this do me any good? Will a processor send a “balanced” signal to the crossover, to the amp independent of the source?

I'm not sure here, but my thinking is this.... if you want to bi amp the Warfdales, a splitter of sorts is going to be needed. Perhaps just a Y connnector, and two sets of ICs. one pair for each pair of amps going out to the spakers, plus two sets of speaker cables.... one for the top, one for the lower end.

As long as the Xover in the Warfs is in atct and not defeated somehow, I don't see how a tformer is going to help. As whatever signal is run into them their Xovers are going to cut off at whatever level the signal being fed to them.

Re balanced
I'm guessing here... if a signal is incoming to the pre/proc via SE, it is still a signal. I could then see how it would be passed on via balanced topology.

I could also see how that would not happen.

Call the maker (s) of the pre/proc and ask them.... both questions.
I think part of the reason I found the above Xover is because I would not need to split the signal from the preamp, the Xover does the splitting. I also planned on opening up the speakers and bipassing the first crossover, so at least the sub would be truly active. From what I understand there are two passive crossovers in a 3way speaker. 1 b/t bass and mid-high and 1 b/t mid and high.
I spent some time reading/looking at y splitters but my feeling there is no advantage to passive bi-amping. one, the signal would be passivly split. two, the amps would still be sending a full range signal to each speaker. three, all the passive xovers in the speaker would still be used, giving no realy sonic or power advantage.
And btw, if anyone has a better Xover suggestion in the <$200 range I'm all ears!

your point is a good one on the balanced/unbalanced signal. Whatever preamp I research, I will need to find out specifically if it will send a balanced signal independant of the source.