Currently (June 2019), https://takeout.google.com/ has options to either perform a one-time export or to schedule exports every 2 months for a year (6 archives).
The archive can be delivered as a download link via email or added to Drive/Dropbox/OneDrive/Box.
You can request to download all your Facebook information.
You can find this on Settings > Your Facebook Information > Download Your Information.
Deselect all and select Photos and Videos.
This will include all your photos and you can set the media quality to High.
Instagram has an API that you can use that might suite your needs. It should work in whatever language you want to use as long as it has the ability to consume an API.
Any questions about how to use a language to query the API would need to be posted on StackOverflow and not here.
After having to talked to Google support, and run my own tests - Yes, anybody can permanently and unrecoverably delete any and all information they have write access to in Google Drive in a matter of seconds (obviously, save for any other backups you have manually set up).
Seems like a massive security failure to me, but oh well. We have resolved to ...
Google Sheets doesn't include a built-in feature to open Excel files from Dropbox but maybe there are Google Sheets add-on that does that and if not you could use Google Apps Script to automate the procedure that you are already doing. By the other hand there are services like IFTT, Zapier among others that could help you.
To learn the pretty basics about ...