Just to note that I've been working from home for nearly 14 years now, and I have always broken almost all of these rules. Except the one about loving what I do. Because I do love it: if I didn't, I'd get a different job.

I don't have a set routine. I don't avoid the sofa. If I want a mid-afternoon nap, I have one. If I don't get up until noon, that's fine. I monitor my outputs, not my inputs -- which is why you'll sometimes find me working at 5am on a Sunday morning, or over a public holiday, and why you'll sometimes find me shopping or in the pub during office hours. (Not to mention the gym: I try to schedule my exercise for times when everyone with an office job is at their desk.)

Outputs. As long as the work gets done, you're good to go. And apart from that, make sure you still have a social life.

Drawbacks: it's easy to vanish down the rabbit hole: working in an office is an oft-unacknowledged social experience, and even though your co-workers may not be people who'd hang out with otherwise, human contact is important.