Re: CiviCRM contribs/extensions - any scripting language limitation?
It depends.

If it's an extension that does something that I need, I would use python (well, it's already installed on all my servers, but would have installed it).

It will however limit the distribution to those that have root access to their servers and can install whatever they want on it, so probably make more sense for "big install" civi.

By the way, by extension, you mean "additional features", not "civicrm native extension", right?

If it's the former, I feel ok with python interfacing with civi (eg. via the rest interface), cleanclothes has for instance a complete frontend developed in python that only uses civi as a backend (and for the most advanced features if I recall)

If it were the latter, I would be concerned having php calling somehow python, mostly because I'm not even sure how it could work cleanly.

You need to tell us more about what your extension does.