I would call those pretty reasonable. Smoking and children are big things, and can have pretty drastic affects on your lifestyle. I think sometimes when a person says they have "dealbreakers," some people assume that means they're going to be an asshole to anyone with those qualities that seeks a relationship with them. But that isn't really how it works in practice. You just...don't pursue a romantic relationship with them. Or if you start and then realize later on, you just break it off like you'd break off any relationship that just doesn't work out.
I think people CAN get too picky about relationships. To me, someone is too picky when they worry about little things in relationships, or consistently expect very specific behaviors of their partner without worrying about their own behaviors. For example, someone who would break up over them not leaving the toilet seat down, or get very upset if they fart nearby, or expecting flowers every Valentine's, or constantly trumpet how they need to be "treated right." Everybody's partner has a few quirks or habits that get on their nerves, but people in healthy relationships find compromises and balances. To expect your partner to do NOTHING that might annoy or frustrate you is simply unreasonable. And it's also unreasonable to have a long and specific laundry list of things that your partner must do for you, without ever considering what you should do for your partner.
Now, I did see an interesting article recently called "She Divorced Me Because I Left Dishes by the Sink." [http://mustbethistalltoride.com/2016/01/14/she-divorced-me-because-i-left-dishes-by-the-sink/] The title is a bit of a fake-out. The writer's point isn't that his wife divorced him over something petty, but rather that the little things he neglected to became an indication that he didn't respect her wishes or opinions. He didn't care if a glass stayed by the sink a few days before making it into the washer, but SHE did. And he knew she did. The gesture of putting the glass in the sink was not a great sacrifice on his part, and doing so put a lot less stress on her in the long run. Of course there is a point where reasonable requests end and nagging begins, but if little things are taking a toll on the relationship, chances are it's a lot more nuanced than "He doesn't put his dishes away when he's done" or "She doesn't take out the trash when it's full."
So, yeah. It's not always black and white, and the limits in every relationship are different. Ultimately, when you're with a person you want them to be as happy and content with your situation as you are. If they aren't, or neither of you is happy, then something isn't right. Of course perfect balance all the time is impossible, but as long as you're both aware of when things shift and are willing to react accordingly, then things will work out in the end.