"1. You do not have to believe in the supernatural in order to follow a Christlike path."
No, but if you believe that Jesus was only a man, however wise, then you're free (in fact, I'd argue that you're morally obligated) to decide for yourself which of his teachings were true. (Cafeteria Christianity, here we come!) More to the point, if you see Jesus as merely a great teacher, then odds are good that you also acknowledge him as one of many great teachers - and at that point, you're not so much following a Christlike path as you are trying to figure out how best to act morally.
"2. If you don’t feel comfortable praying to something or someone, then just pray on or about something."
Or, you know, just don't pray. It's not that I don't pray because I'm uncomfortable with the practice; I don't pray because prayer does nothing for me. And while I don't want to get into a big semantic argument about what exactly constitutes prayer, it does seem to me that if nothing is listening, then you're not exactly praying. You're just thinking. Reflecting. Contemplating, maybe. Which are all good and valuable practices in their own right, so why label them with a fancier name?
"3. Christianity is an ongoing practice, not a one time event."
I'm honestly not sure what to make of this. It seems like something you ought to be saying to Christians, not to non-Christians. Yes, of course Christianity is an ongoing practice - in no small part because, at least as I was raised to understand it, a huge amount of Christianity is about learning to be a good person, and being a good person is inevitably a matter of constant work, reflection, and refinement. And yes, despite what some Christians claim, as an unbeliever I shouldn't expect Christians to be immediately redeemed into better people. And, personally, I don't. As far as I can tell, becoming a better person is (like so much else) dependent on the amount of effort you put into trying become a better person; it doesn't have anything to do (pro or con) with becoming a Christian per se. (Though of course, becoming a Christian can certainly inspire someone to try to become a better person.)
"4. You don’t need church to be a Christian, but doing it alone is not easy."
Again - and maybe I'm misreading the point of this whole list - but this seems relevant to Christians and would-be Christians, but not to non-Christians. It may be true, but as a non-believer why should I care?
Going back to Point One, if I don't believe in the supernatural, then there's nothing all that special about Christianity; or, to put that another way, there's no reason for me to aspire to a Christlike life when I can aspire to living a good life that draws on the wisdom of many great teachers. There's no particular reason for me, as a non-believer, to want to be a Christian or be seen as a Christian.
...That said, I would love to see more of Christianity embrace the idea of the Kingdom of Heaven as something that desperately needs to be built here on Earth - an idea, I might add, that seems to be directly supported by Scripture.
"5. Just being a “good person” or “not hurting anyone else” isn’t enough."
Why not? The devil, as they say, is in the details. Sure, your daughter may have learned these principles in her first day at school (or, more likely, even before that) but learning how best to apply them (in all of life's wide variety of situations) is the study of a lifetime. That's true whether your idea of being a good person includes "love God", or whether it's only "love your neighbor as yourself". (Yes, in fact, Jesus himself seems to have suggested that all the law and prophets are direct outgrowths of Trying Not To Be A Dick.)
You seem to be saying that we need Christianity, or some sort of Christian belief, to help us evaluate the full effects of our actions, inactions, and behaviors. I disagree. In fact, as far as I can tell, the only way that any of us, Christians and non-Christians alike, manage that sort of evaluation - the kind that leads to moral growth - is through a combination of empathy, rigorous honesty, and intersubjectivity (which is basically a fancy way of saying "listening to each other").
The only reason I can see that Christianity would be required for such a process is if there is, in fact, a supernatural component to being a Christian - if the Almighty somehow explains things, or guides people to understandings that they wouldn't otherwise get. So far, I haven't seen anything to indicate that such is the case - and, again, that goes against the first point on your list.
Having read through this twice - once initially, and again in composing this response - I have the distinct feeling that I'm missing your point. This doesn't seem like Christianity for Non-Christians; it seems more like some ruminations on What True Christianity Is Or Should Be... or maybe How To Be Christian If You've Become Uncomfortable With Christianity Or Churches (But Still Want To Be A Christian). I don't really see how it's Christianity for non-Christians, either in the sense of explaining things to unbelievers, or in the sense of trying to show why Christianity can/should still be inviting to non-believers.
Am I missing something? (Besides, you know, any drive towards religious belief?) If so, what?
There are several other good responses in the comments, so check them out as well.