What is your acceptable offline tolerance to a drivetrain if you can't get it spot on? I am really anal about MM and such. i just put on a new wheel and cog. Now i am a bit off ,but the chain still rides freely. Just about 1/2-1MM to the outside of the chain plate.

1.5 is about the limit, at that point you can get back to .5 mm with a 1mm spacer so there's no reason to be off by more than that.

edit: not that there is any reliable way to measure it this closely.

Ha ha. I am a bit to precise. I just got back from a test spin through the hood and trhen a 2 mile climb at +10% grade. It worked flawlessly. Smoother than before. The only problem ihave with my setup now is that i have external cart bearings on my crank and the cart bearing formula hub. If i want to dial in chainline i would have to s[ace out the chainring . Looks like i am good to go though.
P.S. the cog i got is a german brand(name slips me now) It looks and feels nice.

I thought you could still spacer an external bearing BB.