If what you're saying is true then G should be a high priority this off-season, which means signing a good veteran or drafting an OG in round 1-2......which I'm sure no one wants to hear.
No, you don't. You can draft a guard in round 6 and get a productive starter. Jahri Evans was round #4, for example.
I think they do want a new guard to replace Nesbit, so while Faneca may not be the choice, I'd be surprised if the Saints don't bring in a vet to compete with the guys they already have... and a low round draft pick is still an option.