Do all 12 cards show on your credit report and do all of them report the limit? To my knowledge there's no way for someone reviewing a credit report to see whether you have or have not "carried" a balance, they only know the most recent balance reported for each account. American Express can, of course, see the payment pattern on the accounts they issue.
A credit report will show if you have other types of debt (e.g. mortgage, installment loans), how old these obligations are, how typical they are for your age, occupation, neighborhood, etc.
on the credit report all cards are shown, with payment matrix good (though its only whether i paid, not whether theyre paid in full). only card on there that shows max balance instead of limit is capital one, and maybe the gold? of course the reports does show outstanding balance at time of pull, which is ~avg credit utilization
no mortgage, no car bills, no loans in my name except 2500$ installment student loan
income is senior-level engineering. downside i suppose is only 1yr current residence in downtown area of mid sized city (instead of suburb)