I'm not counting my chickens either, but I am a planner...so I understand the OP's original post completely. I, too, am a little wary of opening my own practice. Having worked as an assistant for a few years, I see the stresses that the dentists deal with as business owners. Hiring, firing, malpractice, quarterly taxes, accounts receivable. There's so much going on outside of the operatory... Quite frankly, I can see where it wears them down. They take all their stress home with them every evening, because at the end of the day, that business is theirs.
I'm not going to rule out owning a practice, as I don't know where I'll be in five years...if I've even made it into dental school; however, I would ideally (at this point in my life, anyway) like to work in an associateship somewhere. I would love to work at the VA, serving our vets, or do work for rural communities. But of course.....this is all years away...
So no, you are not alone in your misgivings. And don't feel bad for planning ahead. You're not assuming acceptance into dental school, just being prepared in case you are. Nothing wrong with that. 😀