Originally Posted by IluvSQ

Yes, once you clear immigration, you can exit the airport.
I will often meet with transitters for dinner/meetings thsi way.

Yes, you then just go through usual intl security.

For second question, you can re-check your bags immed after clearing
immigration/customs; or , if you want - take them with you, then re-check
them at the other terminal after a meeting or whatever.