Quicksy, if your muscles feel flabby or flat on your off days, it's nothing more than glycogen depletion. Try doing some dynamic stretching and/or cardio, and scarf down those carbs. That should help get you looking pumped up even on the days when you aren't lifting. You may also experience loss in water volume in the muscles if you're experiencing an electrolyte imbalance, which can in fact be brought on by overly strenuous exercise coupled with excessive water drinking.
About working out 7 days a week: that is definitely a no-no. Like cyclops said, you shouldn't work out more than 4-5 days a week on a split program, or 3 days on a full body cycle. 2 days off will not hinder your progress in any way. As a part of my bodybuilding program, HST (hypertrophy specific training), I recently took 12 days off to let my muscles 'decondition', causing them to respong to growth stimuli better once I started hitting the
weights again. I got sick at the end of my strategic deconditioning period, which prolonged it to 16 days. During that time, it seemed as if though my muscles had inflated and I had packed on some fat to boot. Of course, this was simply due to the bulk of the water
weight in my muscles draining out into the surrounding tissues, causing me to look fatter and less muscular, from not being able to work out or even move around much (I had a nasty infection which went from my ears to my throat, and finally to my eyes... I was pretty much out of it). It didn't take me long to regain that muscular and hard look after I got better and was able to resume lifting again, though.
You should definitely incorporate lower body training into your lifting regime, btw. If you can't think of any other reason to do so, try this: the muscles of your legs contain a lot of bulk, and you can add on a lot of general muscle
weight by building them up. After all, is it not a big part of the whole bodybuilding game to be able to brag about how much you weigh? That, and scawny legs look incredibly ridiculous if coupled with a beefy torso.