Can encrypt_password and encrypt_form be used to encrypt information before it is sent via plain text from the browser to the server?

I am very new to this but want to try to better understand.

Use case: passwords over http
When someone logs into a Drupal site, http://mysite.com, the password is sent over via plain text.
I have heard this before and just want to be sure. Please correct me if I am wrong.

Now i could use encrypt_password and encrypt to encrypt the password so that the password and username would be encrypted but still sent over plain text.

Use case: form information
If someone fills out a form on the Drupal website, the information is sent over in plain text.
I have heard this before and just want to be sure. Please correct me if I am wrong.

I could use encrypt_form and encrypt and the form information would be encrypted and still sent over plain text.

Please confirm.

Use case: SSL
Do I need encrypt if I am using SSL on my site exclusively?
Should I use encrypt if SSL is enabled but not required? So the site is in mixed mode?
Is it best to force pages that have information that should be protected to use SSL?

Is there an advantage of using encrypt with SSL?

Thanks so much for answering these questions...

-encrypt, security NOOB!