I have run across threads with similar questions in both mozilla support and reddit, but as they are old and archived I cannot add additional info or request clarification, so here is (yet another) new one- I understand you can go into manage data in settings to delete what you want, however in mine it only shows a handful of most recent (opened today or currently open) since my settings clears history and deletes cookies upon exiting ff.

Cookies and Site Data section shows only 40.7mb of data is stored and in Manage Data only shows 8 sites... Clear Data area, with only these two boxes selected (attached) and 'everything' (time) still only around 50mb. My storage/default folder has 1005 folders and the data is over 1.5gb; I would like to manually delete all of this and as others have tried to ask, am wondering if this is ok to manually select them and delete in windows, or using windows %appdata%(?) and if so, will the sync feature (if I just clicked 'sync now') still retain all my bookmarks when I relaunch ff? Not concerned about any browsing/form history or passwords, only bookmarks.