It's been a long time since I made shrimp scampi but you certainly have all the right ingredients!!! I don't think I can really add anything except to say I have also added a bit of cayenne pepper to mine - not a substantial amount but "some". What if you thicken the sauce a bit - not really to thicken but just to give it some body - with a roux. Or, very lightly dredge your shrimp in a bit of cornstarch/flour first, then what falls off will give the sauce a bit of body?
I'm just brainstorming...
I served mine in individual dishes one time with wild rice on the bottom - the wild rice was REALLY good with it!
"Count yourself...you ain't so many" - quote from Buck's Daddy
Ive never made shrimp scampi, however I have eaten it in many different restaurants and alot of them had what seemed like bread crumbs in the sauce (I dont mean the shrimp was breaded). Maybe that would add another layer of flavor?
Im no cook, ya know, but thought that might help ; )