G-d Explanation

"G-d" is the traditional way of writing God. Out of our great respect for Him, we do not want to cause any desecration of His name. This would include discarding His name. Therefore we use a dash, so as not to write out His full name.

Yes, certainly He is higher than this name that us humans have selected. However, this is indeed our way of communicating His being, and therefore we treat it in an extra sensitive fashion.

With respect to deleting a file with His name, this does not present the same problem. In truth, every word on the screen is replenishing itself several times a second. So, His name is disappearing and reappearing.