Balance is a separate FICO code. Sometimes you'll see a reason code saying "the balances on your revolving accounts are too high".

Per util, ideally you'd want to have all CCs at $0 but one and get the one to under 9% of the CL. YMMV on everyone's credit of course. But I personally have seen a negative comment of high util at 16 or 18% (I'd have to dig up old reports...def. under 20%). It's YMMV on your credit and scoring bucket. Some can have high util at 50% and not see the comment.