I agree with the OP. a penetrating pass rushing 3-tech is priority numero uno. Whether that's achieved by bringing in a FA, trading for a vet, or drafting one early in the draft, I neither know nor care. I just know it's a priority because the entire personality of our defense changed when we lost Jason Jones. And that sucks.
The only way we need to even start thinking about getting a starting Leo is if the Clem we get back in September is significantly less than the Clem we had back in December. What we DO need though is adequate depth at Leo (or to figure out a means to better mobilize what we've got because Irvin and Scruggs are good football players). That being said though, I think Irvin will figure it out. In that Atlanta game, he looked like he was trying extra hard not to screw up. That's a recipe for mediocrity when you play DE like Bruce does. He needs to be able to play balls out with only one objective (kill the guy with the ball), and I think Gus (and his doppleganger Todd Wash) had him thinking about too many things. I think Dan Quinn is going to work wonders with Bruce Irvin, and the whole D-line.