After reading this thread, I just feel lucky. I seem to have lucked into the position between benevolent dictator and buddy. A lot of times I end up as a friend who nags. As for being tough, they still come to me with problems. They know I don't bluff when I say something, be it a threat or a promise. They know I'll listen to their side of the story, and I don't usually go off the deep end. As for obedience, well, good luck. Likewise gratitude, although you may hold to a faint hope that she'll acknowledge all your hard work in forty years or so. You're right that it's better to have her behave well in the rest of the world and poorly at home than vice versa.
To answer the original question, yes, you need at least some of your own time, or you'll be worn down like a fingernail by an emery board. Besides, you're the adult and there are some aspects of your life, no matter how small, that are for grownups, not kids; even if it's not having a balanced meal when there are no witnesses, or going to a movie that they're too young for. If nothing else, this lets the teen know they haven't got it all and gives them something to aspire to.
As for the specifics, I agree that you're giving up if you let her smoke because she'll do it anyway. As I said, I'm the mom who nags. You've got a sense of smell, right? So you can call her on it. Granted, she may be too addicted to quit, but why should you be the only one uncomfortable with the situation? If you have the fortitude to deal with the whining, you might just save her a lot of money that she could spend on something better than tobacco and painful medical procedures.
As for not getting up in the morning, well, my mother dropped me off at school on her way to work. Maybe this can work for you as well.(Of course, she'd have killed me if I skipped.) for getting her out of bed, pull off the bedclothes, cross her ankles and roll her out of bed by keeping the feet more or less together and twirling them until she's out of bed. Grogginess and surprise should work in your favor. Cold hands are a plus. And make sure she can't just reach out and grab the blanket. I only had to do this once.
One thing that works sometimes is giving a reason for something that they can understand. My uncle Jim (four years older than me) was a regular wolverine of a hellion in his teens, always getting into trouble in school. Then he figured it out...he liked the good things in life. If he wanted the good things in life he'd need money. To get money he'd need a job. To get enough money for the lifestyle he wanted, he'd need a good job, and that meant a college degree. Once he figured out a good reason to get good grades, he got them, got the degree, got the job he wanted. He was still a wolverine of a hellion, but his parents slept better at night, and were proud to attend all his graduations, through the doctorate.