Howdy Unseen and welcome to the forums!

i generally advise people to roll new characters... so their skill as a multi-boxer grows as they level up. this allows you to fit new powers into your keyboard plan as you go... increasing your familiarity with it.. making it almost 2nd nature.

starting off with 70s would put you at a disadvantage as the stuff you'd be up against would not be very tolerant of someone fumbling around with their setup.