1) The Auto-Import options are in:
Tools > Options > Library & Folders > Auto-Import Folders > Add Folder...
Tools > Options > Library & Folders > Auto-Import Folders > Add Folder... > Advanced
Tools > Options > Library & Folders > Auto-Import Folders > Options
In there you can disable the feature (untick everything) or manually add/remove folders and set the folder specific file types.
Personally, I use only a couple of dedicated import locations and most of the time I have the background importer disabled. I have added the "Run Auto-Import Now" button on the top toolbar so that I can quickly run it when preferred:
Right-click the top toolbar to configure the buttons.
2) To disable file tagging:
Tools > Options > General > Importing & Tagging > untick "Update tags when file info changes"
All changes will still be stored in the library (aka database) and can be applied to the files later.