Lots going on in your post, so forgive me while I quote/address each point.
Firstly, WordPress should have a Link to show the existing Version of WordPress on one's Desktop.
Uh, as WordPress runs on a web server and not your desktop, what would that accomplish even if you could do that...? When you log into your WordPress dashboard you get notified about any updates to the WordPress version.
Secondly, it should provide a Menu/ Option to delete an 'Autosave' and Old Redundant Revisions.
Revisions saved my bacon on one occasion. Perhaps one of these plugins can help you?
Thirdly, there should be a mechanism to Upgrade to newer Versions of WordPress -- without losing the database (existing posts and comments)
Upgrading to newer versions doesn't lose anything from the database.
However, sometimes servers and configurations have problems and that's why it is critical that you make and keep full file and database backups prior to any upgrade.
and the modifications made to the Themes files
Please review child themes. You should never modify any theme (or file) that comes with WordPress and doing so sets you up for huge amounts of pain and suffering down the line.
Fourthly, I would love to hear as to how I am receiving emails (Notifications) whenever someone posts a 'Comment' to my Post -- because my Server (hosting service) does not support PERL? Are these mails being sent via your servers, please?
You should speak with your host, it's whats delivering your email. Mail delivery (and WordPress) does not depend PERL or any other server.