Some small things to remember:
1) Stainless is a poor choice for swords. If a sword is made of stainless, hang it on your wall.
2) Spot welding a questionable tang to a stainless blade is not "differentially heat treating". It's potentially killing your neighbor when the whole thing snaps during your water bottle slashing session. Hang on the wall.
3) Hattori Hanzo frequents neither QVC nor the swap meet/flea market circuit. These are not the outlets for real swords. Hang it on your wall.
4) In my sword classes, you bow to the sword. The sword is treated with more reverence than the instructor. You don't touch another guys sword, period. You spend a couple of years with your wood sword before the training wheels come off and you can even touch a real one.
If you bang the flat repeatedly on a table, you should be hung on a wall.