When I search in the Search box in Bookmarks, after it finds the bookmark, is there a way to check its location (in what Bookmarks folder it is saved)?

I am using Opera Mini on Android Device (Nokie G50)
The search bar is set by default on Google and when I click the small arrow to explore other search options I see only ones I am not interested in (Wikipedia, eBay and Amazon)
How to change it altogether, for example to Duck Duck Go?

Sometimes when I get a notification from websites, such as Google, for a new sign-in attempt, for example if I cleared cookies or something similar, they list the browser as Chrome or Chromium rather than Opera.
Why is that?
I hope I kind of clarified my question.

When I click on a mailto: link (for example an envelope icon) on a certain website in order to send an article to a friend via email, it opens up Outlook 2016 app.
How do I make it to open up Gmail webmail instead?
Is it a browser setting?

When I search in the Search box in Bookmarks, after it finds the bookmark, is there a way to check its location (in what Bookmarks folder it is saved)?

When I save a webpage into the Bookmarks (by Ctrl+D), the destination is set to the last one used (where the most recent bookmark was saved to).
Is there a way to make it to go by default to certain folder (I want Other Bookmarks)?

Is it possible to change the Hotkey for certain action, such as, saving a bookmark (default is CTRL+D)?

@leocg @burnout426 I think I figured it out. I was trying to open the tabs from history in a browser window in which they were not opened before. Does it make sense?

@leocg By following instructions you mean the workflow I described above?

When I go to Settings > History > Recently closed > [Any tab in this list]
The tab I choose opens up in a separate browser window than the one I am on
Why is that and is there a way to make it opened in the same browser window I am on?
Additionally, both right and left click on that tab I want to restore will open it.
Why right-click does an action that is usually for left-click?. Can you fix it please?

Is there a way to sync personal settings across different devices?
For example Extensions.
I installed an Extension in one device but can't see it in another one.