yes it's ok to freeze them in the box, yes you can eat them after the bb date. in theory what you can do with your freezer depends on its rating. it will have a number of snowflake type starts - between 1 and 4. see the following from wikipedia
"* / temperature = -6�C. Maximum storage time for frozen food / 1 week
** / temperature = -12�C. Maximum storage time for frozen food / 1 month
*** / temperature = -18�C. Maximum storage time for frozen food / 3 months
**** / temperature = -21�C. Maximum storage time for frozen food / long term, up to 12 months
Fresh food can only be frozen in a freezer with a four star (****) rating."
but in practice you can bend these rules to a very large extent, as long as you're sensible