I think Leno's issue is focus/technique related. At least I hope so. I've seen the backup LT (Lucas) in preseason and he's a train wreck, although he was decent when filling in for Massie on the right side.
As for Long, the coaches need to reevaluate him over the break. If he's not near 100% he will need to be benched, IR'd, or released. Larsen is a serviceable backup, but he's gimpy too, next man up could be Coward. The only issue there is that he's been playing RT since converting from DE.
If Bears can solve RG and get Trubisky and Gabriel back on offense and Nichols and Hicks on defense, they should be in good shape against the Brees-less Saints.