Hey Rob,
According to the article linked in another thread (xxx.555-timer-circuits.com), pin 4 can pose problems. I thought that may be the root of the thumps/bangs/ticks everybody was getting. It seems a simple enough circuit, and I've got a load of some LDRs and 555's coming in the mail - should be here by the end of the week. I don't currently have a BB, but there's a great little shop in town... I can try to get a baby BB and get this thing rockin...see what up.
I've been toying with the notion of doing this by a true bypass kind of thing with a dpdt. I'm not normally for it (

I kinda like tone-suck...), but I think it may help to address some of the volume drop issues...
AND, on that note, you mentioned twice that adding in a boost/buffer would mean adding another pot... not necessarily, right? Couldn't you dial in the right gain with a trimmer, measure with a meter, then stick in the closest regular resistor? (or hell, just keep the trimmer on the board...?)
- Britt
EDIT: AS for the pin 4 issue, the article detailed that when pin 4 drops below 0.8V, it resets the chip. It seems to me (in my limited electronics knowledge) that if a series cap was used, it may help to keep that pin from dropping below that threshold voltage...thoughts?