I'd only add on the topic of fullers my personal experiences with longer blades...
The fullered sword I have have very little flex (if any) when compared to non-fullered swords i have. I can take my 43" war sword, diamond cross section, and hit it on the flat of the blade, between the point of balance and the center of percussion, and the thing wobbles back and forth for a bit. If I do the same test to my 35" Viking blade (fullered), the blade bounces once, then back to true.
So, I'd say the fuller has many purposes, being:
1. Cost effective in steel-poor times to make fulered blades of less material
2. The sword can still retain its lateral strength with reduced mass
3. The fullered blade can be made longer and still be light
4. Fullers can change the handling characteristics of a blade.
Advanced fuller observation: Placement of fullers on blades (especially historic blades) is more than just a cosmetic feature. For instance, compare the fullers in these images:
35inches
43inches
Note that in the first sword, the fuller runs almost all the way to the tip of the sword.
Note that the second sword has a fuller that stops way before the tip of the sword. This changes the properties of the sword's balance, because you've got more metal weight in the tip of the second sword. so if you fuller a sword in certain places, and not in others, you can get a more balanced or neutral feel(longer fuller) or a more point heavy (fuller only runs part of the way of the blade) feel. In other words, sometimes the fullers are used to change the handling characteristics fo a blade, just like "distal tapering"...but that is another story...
Keith