New Blog Template does not transfer buddypress pages

I have a main website with the Business Portfolio theme using membership and buddypress plugins. It has become so large that I need to break it up a bit and have a better front end landing page.

What I am trying to do is clone the maindomain.com site and call it members.domain.com. Then I will revamp maindomain.com as a public site with lots of free information as well as a members log in that will transfer to the members.maindomain.com

I used the New Blog Template to create the members.maindomain.com site and it worked perfectly, but when I tested the site and accessed any of the buddypress pages the web address reverted back to maindomain.com

So, my questions are:

1. When I completely change the maindomain.com to another theme and different content will my buddypress pages on the members.maindomain.com disappear?

2. Is this a security issue with the member.maindomain.com that cannot be fixed with altering the levels in membership?

If I am not proceeding in the correct manner to accomplish my goal is there a better way?

Thanks for any help. ~ JoAnn