If they sign Mack, what position are the Bears going to be looking for in FA to make a splash? What position in the draft would be affected by us getting Mack? I could be wrong, but when I make a list of needs on this team, the only glaring need I see is Pass Rusher. Now, if you see other glaring needs on this roster, please tell me. I really can't find another glaring need.
Probably would consider getting another tackle to replace Massie. But you're right, if you look at the roster, it looks like the Bears' most glaring needs are pass rushers and depth for the most part. Depending on how RRH or Bullard do, there may still be a need for a DE opposite of Hicks.
We dropped big money on CBs so I doubt that'll happen but I'd say that after OLB, RT, and potentially DE, CBs would be the next ones you could arguably upgrade (though if Fuller continues his improvement, this could be completely wrong and despite what Prince got, you could still find a better CB but I'd draft their replacement given the contract lengths).
Depth at certain positions is thin, especially up front. No swing tackle, no back up NT to spell Goldman, and if either Amos or Jackson go down, I wouldn't really want any of the back up S. Either way, I think getting Mack won't necessarily impede the ability to fix these issues, but you'd have less capital to work with (both in draft and in FA).