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Reducing the number of accounts with a balance can only help your FICO. Reducing the utilization can only help, but getting uner 11% is your next threshhold.
Aging of your accounts usually helps your FICO.
The possible FICO downsides: If you get rebucketed, you could see only minimal score increases, or even some FICO score drop short term. But, that being said, there is no way to avoid it if it happens.
Good credit is always the same recipe. Establish credit, conservative use, low number of balances, low DTI and utilization, age, payment history, etc.