You should be able to drop your broadband card in exchange for just using the your blackberry connection and still use a large amount of data as long as you stay within the limits that is on the VZ access manager and your data plan for data usage. (generally speaking).
I have a BB with the broadband connect. Are you saying I could drop the broadband connect if I stay under 5gb? I think with my heaviest month, I've used maybe 1 gig including tethering.