Your problem all arises because you did not set permissions as stated in the install instructions. You need to set the uploads and data folders to 777 at every level.
As far as the login page as long as you have installed correctly integrating with SMF you should be fine. I show this right in the login function in pp-inc.php
Code:
Content visible to verified customers only.
So in your smf settings what do you have set as the default style?