Alexander's a stay-home fighter. He won't travel unless he can secure an advantage on the cards. Jones is at the same level as Brook (though his win over Karass is a little better than anything Brook's got), so it's unlikely he'd risk a tough fight unless there was a title on the line. Malignaggi is the most likely, but it's a pretty crap fight. He offers nothing to test Brook.
He'd be robbed against Alexander even if he beat him. Jones is too dangerous right now and there's no belt on the line. Malignaggi makes the most sense. He'll still be a step up from that Pole he just fought. Then look to fight Berto after that.
Paulie fight won't happen in december and Paulie has said himself that he probably wouldn't fight Brook as he only wants big names at WW and Brook doesn't quite fall into this category yet. If Brook is the biggest name he can get however then maybe. Although I think GBP will 'protect him' a little bit until they get this Brooklyn venture underway which they want him to be a part of.
On Devon Alexander, I don't know much Don King had to do with him being a homer. It might be different with him being at GBP now.
How about Joshua Clottey? I know he's not great but he's tough as nails and has mixed it with some big name's, It's not a bad first fight in the US for Brook IMO