I'll try and answer some of those questions for you.
Can the Super-V be the requirments i crave for??
That one is a subjective question, but I would be willing to bet that the Super-V's will do everything you seek.
Is it a PA speaker or hifi speaker or something in between??
By the way it has been designed and built it is clearly a top level audiophile driver. However, its original intent may have been targeted towards trying to bring high quality to the music production (not reproduction) industry.
It should sound "live" but not shouty, will i have sweet sounding treble like the upper range of a B&W speaker/tweeter for instance?
That is an interesting question. I find the Super-V's to create a very real or live sound. I don't find them shouty or harsh. I have a pet peeve about that type of sound. And I find the sound of the metal dome B&W speakers to be a bit harsh and fatiguing. I can't listen to any B&W speaker that I have heard to date for very long.
The coax driver super-V can go to 18khz i believe. Is this enough?? When i use an equalizer and use the 20khz band i can sure the hear the difference.
My measurements show good upper end extension. I don't see any issues there.
When you boost a signal with an EQ at 20kHz you are also boosting levels at 10kHz and even 5kHz. So I wouldn't read too much into that.
Will i have a tight low frequencie pressure as with a box speaker in this open baffle design for dance music for instance??
The Super-V's are much better in that regard than any boxed speaker. Not only is the bass cleaner, tighter, and faster than anything else, but you also won't have the same loading of the room and room boom that you can get from a sealed sub.
Why is the design more complicated then just a wooden plate with the drivers bolt on to?
I didn't think that there were complicated, but everything is like it is for a reason. If the drivers were simply bolted to a baffle then the performance would certainly suffer in many areas.
Is there a reason for the lowest servo sub to face the back??
It is suppose to cancel out some harmonic distortions. It also helps balance out the weight of the speaker and makes it more stable.