I have a social networking site with user- and company profiles. Some profiles have little to no content. One of the users here at moz suggested noindex-ing these profiles. I am still investigating this issue and have some follow up questions:

1. What is the possible gain of no-indexing uninteresting profiles? Especially interested in this since these profiles do bring in long-tail traffic atm.
2. How "irreversable" is introducing a noindex directive? Would everything "return to normal" if I remove te noindex directive?
3. When determining the treshold for having profiles indexed, how should the following items be weighed

• Sum of number of words on the page (comprised of one or more of the following: full name, city, 0 to N company names, bio, activity)
• (unique) Profile picture
• (Nofollowed) Links to user's profiles on social networks  or user's own site.
• Embedded Google Map

Thanks!