The OL improving isn't an "if." They will be improved, period. Don't expect Wisconsin or ND's OL out there, but they will be improved.
LB is far less of an "if" than CBers like to worry about. We worry like this every time, and basically each time someone steps up. If there's one place on the team where we'll reload, it's LB.
And I know there's a question with Hill, not so much Hill, but the experience behind him, but that's similar to many teams every year isn't it? If there's one position that might not have any experience it's QB.