"1. For those of you in serious bug country would you consider a floorless shelter much better than a bivy? If not I might as well get rid of it."
Well, getting rid of it might not be so politically correct. Tarps and netting are not real expensive. You may want to keep it.
I never use a bivy, being more of a full coverage guy. I use a bug tent as needed mostly. That said about 15 years ago I put about severa ounces of bug netting around my tarp. This worked OK, but, it let in an occasional mosquito, blackfly. One bug at night is like a swarm during the day. I removed the bug net perimiter, because it was not effective enough. Your milage may vary. I tried a couple smaller bug bivies, but I would invariably find myself leaning against one side or the other. Not a problem on cooler nights, but on warmer nights, with my arms out, I was bug food where I had leaned against the screen. It seems the mosquitos can bite right through netting and a light long sleeved base layer.
"2. For the forseeable feature my camping is going to be 90% in Virginia where I have family and Colorado with the possiblity of trips to Wyoming or Montana. Anyone ever encounter really bad bugs up there (outside of a swamp)?"
Well, those states are big areas. So, I might suggest putting a floor in rather than just perimiter netting. I don't know if that is possible, without a lot of fussing. It will depend on where you head out. It seems most gear has it's place if the terrain and conditions are correct for it. I would suggest thinking about it, anyway.
Note that in removing the bug net perimiter from the old tarp, I found that the effective dry space was reduced, too. Drips/splash were generally caught by the net. In any type of wind, it needs to be weighted down or staked. In one instance near St. Regis Pond (St. Regis canoe area), the wind was blowing quite hard and the peak of the tarp was coated with bugs, inside. Most were mayflies though…non-biters.