Can a tenure-track job candidate infer any meaning from the response to an initial contact email?
Don't stress out about the responses, since it's nearly impossible to get reliable information by reading between the lines.  The variation in how people might respond is enormous, and unless you really know the people involved it's hard to know what it means.  For example, suppose someone sends a friendly, encouraging reply.  Maybe it means you have a real shot at the job.  Maybe it means they think you have a real shot, but they could be totally wrong.  (Sometimes people on hiring committees have unrealistic beliefs about how everything will play out.)  Maybe it's just their personality and has nothing to do with your chances.  Maybe they are deliberately saying the same thing to everyone in order to avoid awkwardness.  If you don't know them pretty well, all you can do is guess.  Of course a standoffish reply is equally difficult to interpret.  The net effect is that you'll get replies that look like they may contain information, but you really won't know what, if anything, they mean.  It's best to resign yourself to this now, rather than spending a lot of time worrying over how to interpret replies and not actually learning anything valuable in the process.