Adding the <your_file>.desktop you won't "mess with X terminal" that much... You won't touch/edit any configuration files/whatever_else you have in the phone, but just adding a new shortcut description to run a certain command in X Terminal... Nothing else...

Of course, you have to understand what you are doing, otherwise I won't suggest to do anything on your phone.

Icon is simple - you can put "general_refresh" to get attached icon for new shortcut.

Let's call the file mprc.desktop:

[Desktop Entry]
Encoding=UTF-8
Type=Application
Name=MPRC
Exec=/usr/bin/osso-xterm 'tracker-processes --hard-reset'
Icon=general_refresh

After this file added, you'll get a new button in More menu with attached icon, named MPRC