1. It was the first house we bought to live in. When we moved 4 years later to a different part of town, it wasn't selling, so we found someone who wanted to "lease to own." Two years later, they declined to buy it, so we had it back... in worse shape, of course. But we kept the option fee, cleaned it up, and got it sold.
I don't think of that as our first "real" investment, though (even though I know it was). I think of the house next door, a 3br/1ba rental house that we bought when the previous landlord was tired of it. It comes nowhere close to the 50% rule or anything like it (didn't know about those at the time!), but the rent more than covers the mortgage & basic expenses, and we can cover the major upgrades (like the new driveway being put in next week).
2. Pros & cons? Pro: It's close, easy to manage, lets us choose our neighbors. Con: Not really profitable, but we plan on owning it for life, so it will be once our tenants have finished paying the mortgage for us. :)
3. Sure, if you can afford it. But ideally you should learn more about it first. :)