A reseller account is for hosting multiple sites. I'm hosting multiple sites. The hosting company is only concerned that I pay my reseller fees every month - they don't care who I resell to, or how many sites I have in my account. (They do care about the kinds of sites - ie: no warez, porn, MLM, software distribution, music, etc.) They give people the opportunity to make money by reselling web space - I just chose not to make money on it.
Just make sure you work within their terms of service. If there ever was a question about it, I'd just start paying myself for the hosting every month. But, I'm paying a set price for a certain amount of space and bandwidth that allows me to have an unlimited number of domains hosted under a main account, and that's what I'm doing.
I also have a second reseller account with another company. That company charges me a reduced rate for each domain. With that one, I "sell" websites on a subscription basis, pay for each (also on subscription), and I keep the difference. 2 different types of reseller accounts, 2 different uses. (If I wanted to, I could host my sites with this reseller account and still pay a considerably reduced rate for each. Would that be wrong??)
Plus, there are many hosting companies that allow you to have up to 5 or more domains under the same account. (Sometimes free, sometimes a couple of bucks extra as a setup fee.) Is this any different?