Not sure about the LB thing but I agree that we need a playmaker as a safety. Not sure if it need to be Rd 1 as I feel that DL playmaker is integral to this style of defense.
Why not a new LBer? Q and DB are about ready to collect their pensions man.
Q is about done next year, and DB has 2 more years, at the VERY most. I am thinking after next year he will be gone.
There are too many holes to fill on the defensive side of things. Starting with the LBers, and the corners as well. Barber and Kelly are far from spring chickens...and Z-man is an unproven who doesn't even suit up on game day, despite CB depth issues. So take what you will from that.
Address these areas first. Safety next. At least the safeties have some youth to them.