2. Your BlackBerry will use data, regardless if you don't. Connecting the device up on a foreign SIM will still use data. Turn data off at your Manage Connections > Mobile Network options.
3. GPS... Options > Advanced > GPS > Menu > Refresh GPS. Be outside in an open area with no tall buildings surrounding you. Allow it to refresh up to ten minutes, and try a second and third time if needed. You will need to Refresh the GPS anytime you travel far from your previous location (like on a flight) as the ephemeris tables must be downloaded for the device to know where to find the satellites. ephemeris data - How-GPS-Works Glossary
And, ditto on the BlackBerry Data Plan, for those apps.