PhpBB installation in WordPress Site

I am planning to install a PHPBB forum on my existing WordPress website. And, I just have a couple of questions about this installation & integration before I start anything…

The Goal: The End Product That I Envision
A) PHPBB integrated nicely in my WordPress site
B) PHPBB and Current WordPress databases separate
C) Facebook Login to use PHPBB Forum

QUESTIONS:
1) Should I install PHPBB in a separate folder?
2) What plugin do you suggest I use for the integration?
3) What plugin should I use for Facebook Login for the PHPBB forum?
4) Can PHPBB be installed in a separate database from the WordPress database?

I’d appreciate any help or direction with this.

THANK YOU!