The numbers you are seeing in the UI are related to the “verbose localization” feature. Details about how tit can be used to modify the user interface text of your site are here: Find a translation key with verbose localization. The most likely reason you are seeing the numbers is because you have enabled the “verbose localization” site setting:
Just to reiterate this It is much more useful for us to have one issue per topic so we can make use of all of the features to better organise our content.
Moin has very helpfully answered in different posts to make it easier to split out the answers, if you wouldn’t mind splitting your extra questions up into new topics.