Ok, I found out some solutions to the bugs that I encountered. First, for the blank index page, I found out on the top of admin/index.php, you need to add // before //REPLACE with, so that eliminated bug no 1 :)
Second, for general.php, function tep_admin_check_login(), replace FILENAME_FORBIDEN with FILENAME_FORBIDDEN. This kinda solves the FILENAME_FORBIDEN error that I encountered. I am still working on solving why Catalog, Tools, and Orders won't work eventhough I declared permission for those in super admin file access.