Hi Mike, thanks for reading it :)
The North Caucasus are definitely worth visiting, but keep an eye on the news. Dagestan has a steady insurgency, as does Ingushetia, but it is security forces rather than foreigners that are targeted. LP seems overly-negative about the region (I guess it suits them not to have to send someone there and research the area...) but if you can get around Central Asia and other parts of Russia you should have no problem here. People are super-friendly.
I'd be happy to answer any questions I can, leave a comment on the website or send me a PM and I'll get back to you. Please bear in mind though that I drive everywhere in my own vehicle, so I can't help with anything to do with public transport. I also don't stay in hotels!
As far as I know, the border between Russia and Azerbaijan IS open to anyone (with visas of course) and I have read a couple of reports of people crossing. I am planning on trying it in 2015, but until now I have not done it.
In general, if you want to see a good swathe of the North Caucasus I would start in Sochi and head east through all the republics, as I did. If you only have time to quickly pass through, I would go from Baku to Astrakhan and stop in Derbent. There are definitely trains running on this line, local Dagestani friends of mine take them to get to Baku.
EO
EurasiaOverland: a memoir of a 2,058-day, 252,151-kilometre road journey through all of the Former USSR, Turkey, Iran, Iraq, Afghanistan, Pakistan, India, Bangladesh, Nepal and Mongolia