It's difficult about the domain thing, I always think I can sell the domain everytime I buy it, in theory it's possible.. but most of the times it's hard to get a GOOD price for it
About the warnings.. Everyone told me not to start a blog about loans as there were just too much, I started a Dutch loans blog and it turns out great, an average click is around 3,43$ at the moment and I get a few each day which makes me feel a little bit rich I also have a lot of other plans regarding to that, but I prefer this vision on the warnings topic:
Do things you normally won't do - think outside the box - so try stuff you think you couldn't... Once it turns out well (it's gonna be hard, you'll need to try a lot) it will be fun! The owners of Google had the same thing, they started a search engine... In that time there were only a few pages with text, but making it was so fun, now look at Google, it's the #1 search engine used by tons of people daily!
But apart from those things the other things are true and this is another great article, thanks you very much