Hi
Since the introduction of Betfair's new API last year, Betfair have lifted the data request limit, and that has been reflected in the updates to the software Connection Monitor. The only thing you need to keep an eye on will be transactions (bets) per hour, which is 1000/hr after which you may incur a charge, and there is a setting in the Connection Monitor for that.
As for the rest, if as you say you do not consistently bet below the minimum, and use real money from time-to-time, you will be fine.
Betfair would rightly query someone who, for example, uses test mode to collect data from their servers and never pays any commission for that service.
I don't think you have anything to worry about.