Dear Marcel,
You don't need an author.php file if you use the Views plugin. You can make a View that shows only the posts of the current author like this:
http://wp-types.com/documentation/user-guides/filtering-views-query-by-author/
Then you can include that View in a page that you can call "Profile". The View Template for each post can include a link to the author using this short code:
http://wp-types.com/documentation/views-shortcodes/#wpv-post-author
If you prefer to go with author.php, there is extensive information about Author templates in the codex:
http://codex.wordpress.org/Author_Templates
Finally, you can link to the login page with the return_to parameter:
wp-login.php?return_to=/profile/
Please let me know if you are satisfied with my answer and if I can help you with any other questions you might have.
Regards,
Caridad