the whole beer before liquor thing is an excuse made for women
im on 5 beers and 8 shots of vodka and i can tell you as sober as possible that if i have any problems in the near future it isnt from mixing alcohol and beer
ive gone out and had 10 beers before taking any shots and been fine, i guess some people are different but i think its a cop out for people who get sick
the only thing i would worry about is mixing beer with one hard liquor and then several other types of hard liquor, i remember at an open bar wedding when i had like 7 different mixed drinks and a couple heines..... it was curtains. GAME OVER