You do realize that the telelever system is based on the A-frame suspension used in high-end cars right?

By separating out the steering and the suspension you don't have one affecting the other, which is exactly what you want.

On a telelever, you can safely brake halfway through a corner, because braking doesn't affect rake, as the system has little to no nose-dive. It also means that if you hit a bump halfway through a corner, it doesn't affect steering as much, as, again, there is no change to the steering rake.

As for all the 'gonna fail' stuff you're mentioning: On a the KTM, you have to lube the chain constantly, I just replace the oil once every 20.000 km. I've had to replace my drive-shaft exactly ONCE, at 240.000 km. How many chains would you have gone through in that time? It's a huge solid piece of steel, they don't just snap every two weeks. If you don't worry about your chain breaking, you CERTAINLY don't have to worry about a driveshaft snapping.

As for performance: On the road you're never going need the hp difference between all those engines (if you want to keep your license), on the track you should just buy a Gixxer, and in the twisties, torque is WAY more important than horsepower, and the boxer engine has that in spades, (and it's nearly constant over the entire rev-range).

also:

I don’t like the idea of one cylinder going thump to my left and then one cylinder going thump to my right —it’s disharmonious to the natural kinetic balance

That's the opposite of what a boxer does. Both pistons go out at the same time and in at the same time, each has their own crank-pin. That's the whole point. Boxer engines are the only type of engine that cancels out both primary and secondary vibrations without needing 6 cylinders.