on Pot

[KLEIN_B at a1.wdc.com]

No this isn't about drugs.......

Another thing,
If you do use a pot from the negative input to ground, it is critical
where you choose to ground the line.  In high gain situations you could
get a ground-loop, resulting in oscillations.  You may have to experiment
with this to get it right.  Also, I assume that you will then be requiring
a cap in series with the pot so you do not amplify dc offsets.

If it were me, I'd try the feedback pot version first.  If it opens 
while you turn it so what?  Probably just as disruptive as if you
had a full level signal and it dropped OUT due to wiper movement......

Don't let all this discussion prevent you from trying to build it.
In fact FORGET about all the protection worries you've had and just
build it.  That protection stuff is smart to do etc. but there is a
lot of stuff out there that doesn't have it.  

klein_b at a1.wdc.com