I couldn't remember exactly why I was getting so hung up on "earth-like" and "habitable zone" having any real meaning for life or habitability
but it has been bothering me because I knew that while it is important to investigate these targets, those qualities alone don't actually mean fuck all.
This got me searching my email because I remember getting an internal release pre-print last year about the weather on ProxCen B, an earth-like planet in the habitable zone only 4Ly away, literally our closest extra solar planet and it happens to be E-L and in H zone.
Paper has since been published so here is the link
https://arxiv.org/pdf/1609.09076.pdf
Highlights a lot of factors that even I hadn't really thought about in terms of exoplanet viability from an astrobiology standpoint. From the abstract of the paper...
"the planet is subject to stellar wind pressures
of more than 2000 times those experienced by Earth from the solar wind. During an
orbit, Proxima b is also subject to pressure changes of 1 to 3 orders of magnitude on
timescales of a day. Its magnetopause standoff distance consequently undergoes sudden
and periodic changes by a factor of 2 to 5. Proxima b will traverse the interplanetary
current sheet twice each orbit, and likely crosses into regions of subsonic wind quite
frequently. These effects should be taken into account in any physically realistic
assessment or prediction of its atmospheric reservoir, characteristics and loss."
Anyway, the new exoplanets are still interesting but it is good to remember that space is complicated, and trying to reduce viability down to just a few sweeping generalizations is bad.