4mg clonazepam seems to be a good dose for moderate effects for me and not dangerous or worry of blackout, I have tolerance to benzos, but nothing major, usually abuse them recreation-ally once a week or so for the past 3-4 months.
I never had any problems drinking on benzos, i've done up to 8mg of etizolam at once and had 4 beers before it and been fine, i've also done 4mg etizolam and went out with the intentions of not drinking, met with friends at the club and just started doing shots and cocktails and was fine. Of course this combination is not healthy or safe but a couple of units of alcohol really isn't going to kill you.