This is a question that I was researching myself several months ago.
When displaying message previews, Microsoft do take extra precautions to protect against maliciously crafted emails being able to infect systems. Mostly that protection is enough (in that it is safer to preview a message than normally view it). However, over the years there have been a handful of instances where that extra protection has been breached or shown to be inadequate (sorry, I so not have any examples - I'm going from memory of my research several months ago.). I still prefer to work with the reading pane and preview pane both turned off.
In the more recent versions of Outlook, you can't even get to view the internet message headers without opening the message first (I generally like to look at the Internet headers to determine the provenance of suspect emails). As you say, some dangerous emails look VERY good these days. One spam attack on my office network this week was so good, that although, as a human, I knew that the email was spam, syntactically the messages were very good, and the only thing I could find wrong with them was in its message headers - the senders IP would not correlate with the purported sender).
At home I use a tool called Pocketknife peek ( http://www.xintercept.com/peek/pkpeek.htm ) to inspect suspect email. I use it with Outlook 2007, but the blurb says it has been updated for 2013, and best of all it is free for personal use. I've used this product for several years and find it invaluable for these checks (however you do still need to be on your guard, to decide which messages to inspect with it).