Ok the reason for the full length is because of the number of customers we have building funky drift cars, with the full length lines you can use different calipers, or fit S14 calipers to an S13, etc. It just gives a whole lot more flexibility for all the different cars out there. In terms of flex/pedal response, you don't need to worry about that, as long as the line is secured along it's route there will be no difference between it and a hardline.
As for the seal on the caliper, it seals with a taper rather than a washer or anything, so that's just fine.
