You can set this pref to false on the about:config page.

• about:config => browser.tabs.selectOwnerOnClose = false

You can open the about:config page via the location/address bar. On the warning page, you can click "Accept the Risk and Continue" to open about:config.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Thanks.

1 thing still remains: When I restore previous session so that all tabs are created but not yet loaded. And I then click on few tabs to get them to load. And then jump somewhere in the middle and then close that tab, then it till jumps back to last loaded tab rather than activating this sleeping/suspended (what's the correct technical term for that?) tab. Is there also option for that to jump right even if it means waking up sleeping tab?

One more problem.

selectOwnerOnClose does not always work. Sometimes it still jumps somewhere else.

There is an extension which allows you to choose which tab is activated. You have to use it to create shortcuts or in your case one shortcut.

https://addons.mozilla.org/en-GB/firefox/addon/select-after-closing-current/