Mounting via fstab will likely help. Make sure that your user has proper permissions on the directory that you mount the drive to. Steam is running as your user and won't be able to read/write to a directory (for example) owned by root with 755 permissions.
Often I don't find myself navigating directories when I reach for my file manager, but looking for something. Learning to use find or fzf gets rid of a fair amount of shuffling through your file system. Also, don't be afraid to type out full paths when performing copy or move commands. There isn't any reason to go to
/home/documents/12/directories/deep when you can simply put the path in your ls or other command. And of course, tab complete is your friend (/ho[tab}/doc[tab]/12/[tab]/deep, etc...)