Circle tracker's rule of thumb: "Lean is mean, but fat's where it's at!"
Yes, running the mixture lean will produce more power, until... You reach the point where the cylinder can't get cool because it's TOO lean. Running a tad rich may use a bit more fuel, and it may cost you one or two horsepower. It will not, however, damage your engine the way too lean can. Running TOO rich (black smoke coming out at speed) will wash the walls as previously mentioned (the raw gas breaks up the oil film on the cylinder wall). That will lead to premature ring failure and/or galling of the piston.
Any vacuum secondary carb will be "self-regulating" when it comes to volume. We've found the Q-Jet and genuine Carters to be better than the others. Lots of reports of tuning problems with Edelbrocks (Carter clones).