Some things that could be done without major scheme or roster changes to help our defense right now...
Without any doubt at this point, safety is our biggest problem....on either side of the ball and no matter how you shake it. Without any doubt our best ball hawk (who sadly lacks ideal size for full time outside corner) is Boykin. He has skills for zone coverage, and can make open field tackles. However Boykin isn't even on the field for all of our defensive snaps (62% the last game for example) at present since he is the nickel corner. Why not play him at FS and move him up to slot on a percentage only basis if the mathchups allows it? He has to be better than any of our top 4 safeties in coverage, and is also a better open field tackler than possibly all of them at present. On possible running downs, have the other safety next to him playing inside the box since he lacks size.
The weak pass rush
It's quite simple. On obvious passing downs only, switch to a 4-3 front and put Curry, Graham, Cox, and a 4th guy not named Cole (he's getting old and lacking short space explosion) all on the field together. This would equal instant and more consistent pass rush. Against pass happy teams, Curry could maybe even play 3-4 DE on more of the non-obvious passing downs as well.
I don't think these things are either unworkable or rocket science. In fact, the trickery involved is far less elaborate than the various wacky passing down fronts that the Dcoordinator has dreamed up thus far. It's certainly better than lining up Boykin at OLB....what the bejesus was that??!?!