Level of Security - Membership PlugIn

I own and operate a web business and just came across WPMUDEV Site. Awesome, really great.

I have downloaded the Membership Plugin for my client who is a large organization website.

They have over 50+ members and need a private secured members area where members can log in with user name & password to download, view, print files etc.

Few questions please - please can you get back to me asap.

1) Can the membership plug in, working for different sections on a page (i.e. a page for downloads, a page for member profiles, a page for financial statements etc.) or do I have to put everything on one page and lock one page. Can more pages be locked, with user id and password to gain access.

2) What is the level of security of this plug in. Can spammers, junk or people intent on gaining access - gain access ? Or can the code be copied so people can copy to log in?

I have no intention of doing this, but am concerned about other internet users. Ideally we want our members to have access, and only members.

Any help greatly appreciated and I look forward to the replies.

Many thanks.