Here are some highlights from our San Francisco 49ers chat, which was held earlier Thursday:Curt from Canada: How worried are you about our secondary?Bill Williamson: If they get a top CB in the draft they should be just fine. There's talent there. Culliver is good. But with that said, I think it would have benefited them to re-sign T. Brown or if they signed Thurmond.Jason from Southern Calif.: Hi Bill, thanks for taking the time. What are the possibilities that the Niners trade up in the first round, say, into the top 10 for a DB like Justin Gilbert or top 20 for a WR like Marquise Lee?