Search:

1) messed up weight distribution

The tsuba is the answer to that. It is not a "hand guard" but serves to bring the center of mass closer to the hands.

2) broken tsuka(s)

This was a...

No. Hilts (tsuka) and sword furniture had to be cleaned and replaced frequently. The tang was usually softer steel forged as a handle right along with the rest of the blade, not added on later, but...

EarthDragon, the Hanwei forge blade is good enough for cutting. You shouldn't risk an expensive blade for training the technique. If you train only in tameshigiri the sheath is not important but if...

The Japanese don't use full tang blades.