The bugs are of interest because:
a) they're there b) they allowed the internal structure of the calculator to be probed c) they allowed new "synthetic" instructions to be coded d) only the earliest calculators have the really interesting bugs (that HP fixed really quickly) and are thus somewhat rarer.
I believe that if you've got bug 3 you've got the lot, as HP rushed to fix it.
Quick battery discharge technique :-)
49 STO 01 SF IND 01
As to the "hard" keys, these are basically worn out. I have never attempted to fix them, and from what I have read it's (at least) a VERY difficult thing to do.
My very early 41C 1937A... has the 1 and 2 keys a bit spongy, but my newer 41C 1944A... has almost completly dead 1 and 2 keys (rather hard is a good description)
In my case the keys no longer click at all (on 1944A), and barely move, but require only about twice the normal effort to actuate. Looking along the face of the keys, these two keys appear to have "sunk" slightly (about 1/2 mm) and are at a bit of an angle. The effect is not visible until you look along the face of the keys, so is cosmetically of little importance.
It's not your 1 and 2 keys too is is? What's so special about these keys?