Warc
You can correct your path statements in the config-int.php file to point correctly to the forum and photopost.
It seems to me with the errors you state you have not entered the correct cookie prefix and
vb license number and or correct paths to gallery/forums
The quick way would be to replace install.php up there and rerun going through all options to make sure they are correct.
You have no admin as when you did not have pp-inc.php your usergroups table did not get created thus you need to go through install again.
You will get some duplicate errors mysql but no worries there. Make sure to correctly input the
vb license number and where it asks for cookie prefix but bb which is the default prefix