1 - What are double semi-colons in the ini ;;? Are they comments?
2 - The line with the db location starts with ;;. If I want to relocate the db do I remove the ;; and change the path? or replace the path after the ;;?
The double semi-colons denote that the setting is the default.
You can set a new path for your database from within Gramps. Go to the Preferences (menu >> Edit >> Preferences) Family Tree tab to set its new location.
After setting the new location and closing Gramps, you will notice that the .ini will have changed. The .ini file stores all of the basic setting for Gramps and any user settings are handled through Preferences. No need to manually edit the .ini.