Don't remind me. That's how we got stuck w/ that damn Takeo Spikes.
I don't think every need can be addressed via free agency, but I do think we can help our offensive line w/ an experienced interior lineman (LeCharles Bentley, perhaps?) and then get a run stuffer for our D line (Ma'ake Kemoeatu of Baltimore; though interest in him is heating up, he still wouldn't break the bank to acquire). Now, if nothing is done in free agency to address the lines, then I'm all for using the first pick to address needs there, as long as we don't reach. You don't just take someone to fill a need if you can get a better player (like Huff) or if the player isn't quite the caliber of the pick (after Ferguson, there's NO offensive lineman I'd take w/ the 8th overall pick).
Now, if there's a trade down, it would depend on where we're trading down to. If we're moving down just a few spots, I'd LOVE to see us address our pass rush by drafting Tamba Hali of PENN STATE. If we're talking about moving down toward the end of the round, then I'd love to see us get a stud like Max Jean-Gilles, the massive road grader who would really help solidify our interior line @ guard.