Hidden files useful?

I have 3 questions regarding backups on Google Drive.

  1. I noticed that a bunch of file uploaded are named like this:
    Can these files be excluded by the syncing?
    In general, can I exclude all the hidden files from syncing?

  2. where exactly is the option to see version history with logseq sync? When I click on the file from the Sync menu, it just shows the current file as it currently is, no history.

  3. what could happen if I use both gDrive sync and logseq sync at the same time? Just to have as many backup systems available as possible in case one of them loses data at some point.

  4. If I just wanted to use Autosync on my Android to sync the graph, what option should I use, between

a) two-way
b) upload only
c) upload then delete
d) upload mirror
e) download only
f) download then delete
g) download mirror

they are all explained here, under “Sync methods”