If I root a Droid ( Razr M) does it get factory reset (erasing all installed apps, etc.)?
If you need to unlock the bootloader first (I could not find that in the instructions; you might check the script for the term oem unlock, usually done via fastboot), this includes a factory-reset, which would mean "all clean up delete", i.e. all data and your self-installed apps would be gone.

Otherwise, if no bootloader-unlock is involved, the rooting process itself would usually not delete anything.