We all want that when the session is restored, all the tabs are not loaded. Let's all be in a friendly voice so that they can give us this opportunity https://bugzilla.mozilla.org/show_bug.cgi?id=1378647

You can edit saved sessions by adding tabs from the current session by dragging. This is implemented.

I do not understand your third remark. If it is not difficult for you - write to e-mail.