Rename screencapture program
I think it is not that easy, but it is possible.
When calling


  which screencapture


I get


  /usr/sbin/screencapture


I enter sudo mode and cd to /usr/sbin


  sudo su 
  cd /usr/sbin


I rename the screencapure programm :


  mv screencapture capturescreen


And after that, I create a symlink to the old one:


  ln -s capturescreen screencapture


now when calling capturescreen, It is called capturescreen.
But when doing CMD+Shift+3, I get the screencapture process.

But You could fix that with creating a Service in Automator and create a Shell-Script-Action, simply calling "capturescreen ~/Desktop/Output.png"

And after that in the System-Preferences, Assign a Shortcut to the Service.

But you could also simply call Terminal and enter "capturescreen ~/Desktop/Output.png"

Even further, you can modify the screencapture action in automator to get the timestamp back and use it as the main tool for schooting screenshots.