I think you've done the right thing in turning her down.
For me, the key difference between renting a room for a fee and paying a commission is that with the former the salon owner knows how much she's going to get at the outset and in some ways it's no skin off her nose if you don't get a lot of clients as she's got her money, as long as you get enough clients to keep renting the room she'll be happy, so you really are self-employed and responsible for your own success. With the latter, the more you earn, the more she earns, so of course she's going to try to pressure you to do everything you can to maximise your takings. The upside is that she will also have an interest in getting people in to you, the downside is that she'll become more involved than you would like and you no longer feel self-employed!
It comes down to what's important to you, and as you say, you don't want to turn into a salesperson obsessed with meeting targets so this obviously isn't the best place for you. Hang on in there - the right place will come along when the time is right.