You wrote "First, how long does it generally take to get your plan switched over to the blackberry internet plan from a original 600 minute plan-I'd hate to get charged for a biscuit load of internet usage?"
I don't know how much a biscuit load
The original 600 minute plan (not BlackBerry) does not allow you to use ANY Internet/data functions. So you can't get charged for not using something.
You got Internet access after the switch was made.
At least that's my interpretation of events.