Hi!
the only way to fix the error (-1) is to reball the baseband.
with baseband dead you will not be able to use wi-fi - the ipad will not see internet.
you can temporary switch it on for example for restoring or updating if you push the modem chip really hard while restoring (needed in the end of operation, 80-100% of the progress), but it won't work after you stop pushing. smb told me that works also to restore an ipad while it is in the freezer, but as you take it off it will lose the signal again. hope that this can help you