Not being from Clarksville, we can't really say what it's like at night in all areas. Although we felt perfectly safe running around all over the place last January after dark.
But I don't see how you can have any trouble with "The Judge" since it's at the courthouse or with "Holy Smokes". "Eau de Arby" should be fine anytime, I would think - and the train station of course. That's only a few off the top of my head without going back to check on the caches there.
So you should have plenty to keep you busy! And interested!!!!! to say the least!
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."