I need to determine who edited some custom fields in the back side of a particular ticket type, and when. Barring that, is it possible to set a main LS Admin profile so they can access the Asset side of the platform, but disallow ticket structure editing?
I assume that you want to see changes made to ticket custom fields on the configuration page. While we do have a report which lists most changes done to configuration. Ticket custom field configuration is not included.
As for the permissions, you can find an overview of them here: https://www.lansweeper.com/kb/103/web-console-user-roles.html
Unfortunately, What I assume you want is not possible. You can either grant someone access to the configuration page or not. At the moment it is a bit of all or nothing. You could revoke other user's access to configuration, which in most cases isn't required.