What is your opinion as to the relative difficulty of forging a blade in this manner?
You may have better luck asking someone who forges blades, but knowing JC, he's probably asked a smith that already.
I've sparred with them quite a bit, and really like them. I've never felt the need for continueing momentum with one (unless you're just talking about keeping the vor), I can only see that leading to deafeat by contra tempo, and you may have felt the need for it from over heavy replicas.?
(Remember that show that was on the history channel for a while, where they decided that you had to keep flails and great axes continually moving to be effective? Geez)
Moving straight to 1/2 swording is negating the great reach advantage you have with them.
From my experience, use of the cross and binding is the real secret to fighting with the greatsword. Use a lot of triangle steps and quartadas. The extra large cross allows so much cool binding work, and really expands the uses of the kron defense, and some really cool techniques can be done by going to the half sword when in a closer bind, or if you want to pfober zagel someone.
As for the wavy blades, I once heard that it was believed that they made deeper or harder to heal wounds, but as far as I know that might be made up or speculation, but either way, we know it's not true now.
The UUUUUU shaped ones (as opposed to S shape) could be "stickier" in a bind.
I think the most obvious, and most likely reasons, were the same for both the sword and the rapier, that it was no different than wearing flashy clothes or a decorative hilt. It was cool looking, stuck out, and didn't interfere with the performance of the weapon.