Do I really need it?

Hi everybody, I'm new here.

I'developing a WpMU+Buddypress site and I expect to have max 200 blogs in it cause is very focused.
I want that every blog has its own simple:press forum.
Is Multidb plugin really necessary? Or, just because there will be not many blogs I could have them running without it?
(attention - newbie question ahead) And if it's necessary when I have to install the plugin (with 256db settings) I didnt understand if I have to write all the lines one by one or there's a simpler method. (I had already take a look at the useful page that generates the infos needed but didn't understand how copy/paste all the lines).
Thank you for Your answers.