By no means should you just use prospector as is. The defaults are pretty good, but if you have a huge project it'll make more sense to do a little configuration, and most of the tools that prospector wraps are configurable. I for one don't use the default lint configuration.
I like dodgy and I actually pull out my secret key from settings.py (I pull it from the system environment). Otherwise you can just disable dodgy by using a custom profile (http://prospector.landscape.io/en/master/profiles.html#enabl...)