Running install is necessary to correct all paths as your config only hosts a master script path and database info. all urls and server paths are stored in the database settings which you could manually edit via a database viewer but I am always going to give you the easiest answer here.
If you correctly reran the install to integrate with vb
you should be able to get into the admin panel if you provided all the proper info for your setup.
Your last error is a common installation mistake number 2 on this tutorial vBulletin Installation/Integration Common Issues and Resolutions.