Step 4 is where you integrate with a forum are you sure the database credentials are correct? Nothing has really changed on install with version 4 in regards to install. There are only a few queries on the upgrade and I have verified all that exists in the install. I have done a couple installs both in the same database and in separate databases without issue
1. Thanks yes thats minor got that
2. Thanks got that
3. You have two entries because you ran the upgrade also. Try redownloading the build and you can upload adm-misc.php to display the right version in admin panel and upload phrases.php and run that to reimport your phrases correctly.