We always like when users dig a little bit into the code and try to see what’s going on 
So the short answer here, as @lmjhe2009 mentioned, is to use Jessie. Although it doesn’t seem like you had any blocker issues with using Wheezy.
Is there a requirement for your project that forces you to use Wheezy? I ask because Raspberry Pi foundation no longer officially supports Wheezy…they only offer Jessie and Jessie Lite on their downloads page for Raspbian. Link. As such, we are considering also not officially supporting Wheezy OS too.
To answer your questions:
-
May be if you are using older version of Wheezy. Will look into this and get back to you.
-
Should not affect anything. Will get back to you on the cause.
-
Will need to get back to you on this.
-
No need to clean up anything. We’re working on a method to uninstall right now that will fully remove Cayenne from the device. There’s a workaround at the bottom of this post: How to Uninstall Cayenne - #6 by CrazyCat
Hope this helps!
-B