OjS installation questions

First of all, I want to thank you for the OjS cms platform.

I have few questions related to installation after I finished to read the ‘Documentation’.

  1. how can I change the absolute URL from www.mydomain.com/index.php/NameOfTheJournal to www.mydomain.com. This is possible from .config file or it can be done via .htaccess?

  2. in the documentation is specified the following:
    “Install OJS so that the files directory is NOT a subdirectory of the OJS installation and cannot be accessed directly via the web server.”
    Can be stored outside the public_html folder, somewhere in the root server? or it means that I can put the OJS files in a ‘obfuscated’ folder with restricted access (e.g. domain.com/my/obfuscated/folder/) and install in the root public_html folder (e.g. domain.com)

  3. can I import the username and passwords (SHA1 hashing) from other platform/database and assign them to be default users. If it is possible, can you tell me in which table are stored?