Securing my drupal website
I serve several Drupal sites on HTTPS, I don't see what Drupal has to do with that, that's the webservers job to handle. You can test the login for yourself in via HTTPS on drupal.org.

For querying the database in a safe fashion, I would recommend Views.
For gathering data with forms, the Webform module. I haven't collected files with Webform, and I'm not sure if that's doable in it's current form. This may require some custom work.

There's a Securing Drupal guide which also specifically mentions getting HTTPS up.