if you are wondering about the charge here's what I would do:
Make an internet connection during peak hours using your phone....download something worthwhile but not too big....maybe a song or some software or something (msft updates maybe)..look at your next statement and see if they charged you for the kb's you downloaded...if they didn't you should be safe...expect the minutes to be going against your plan if you call during peak hours though.
Also try a call during the weekend and download something and check next statement...neither the call nor the kb's should be charged against your plan. I've used verizon while on the road for a few years now and never have been charged for any data call and I stay connected for hours on end during the nights/weekends playing on line games...
Only way to find out about your particular situation is to actually try it and look at the statement.....(all plans are different depending when you initially signed up as their plan rules and regulations are forever changing so they can make a buck or 2)