Re: Quick questions
To change the base profile field group name, go to your WP Dashboard. Under BuddyPress > General settings, you’ll see the first entry allows you to change this.
To set the Activity Stream as your home page, go to your WP Dashboard again. Scroll down to the bottom and, under Settings > Reading, you’ll see the first entry allows you to choose what to display on the front page. Click “A Static Page”, then from the dropdown, select “Activity Stream”. Note that you’ll have to create a page for your Posts Page.
To “lock people out” of certain content areas, you could customize your child-theme templates to display what you want to logged-in/non-logged-in users like here: http://pastebin.com/KFeEAh1Z. Or you could try the s2member plugin: http://www.primothemes.com/post/s2member-membership-plugin-with-paypal/
Hope this helps!