7 unrelated people in a 2400 square foot house in a residential neighborhood? Man, that is going to be a tough one to keep under wraps for an extended period of time. (I agree with one poster, I'm not even sure how you fit that many bedrooms in a house.) Traffic, noise, everything. Nosey neighbors wondering what is up with all the people. We've got unrelated person laws in Fort Worth limited to 5 unrelated people, and this is an issue with student housing near TCU (i.e. homes rented to college kids). I know a couple of savvy operators and sometimes they will have one extra person in there, but there's a lot of activity and other landlords with students living in SFRs so they kind of blend in. If you don't have that kind of camouflage, I worry that you'll stick out like a sore thumb. Sounds like the numbers still work even if you drop down to 5 people, so it's probably not a big deal I guess. (That's assuming there is even such a restriction.)
As an aside, in my area, zoning is generally done by cities, not counties, so I question whether Clark County was the right governmental entity to check. You may be outside of municipal limits, though, so I'm kind of just speculating.