No matter how elite you think your group is, it will eventually die when a few of your so-called "select members" go inactive. You're losing too much potential, early group funds by kicking the ones you consider an "outsider". I've never led a group, but I have a strong say as to the policies we have, heck I even set our weekly GNW victories. All thanks to our rapidly growing group, the many people we helped to power up. We win by numbers, we win by power by a large margin. If you can spare some efforts of actually helping a lot of your members altogether, you'll enjoy the victories it'll give you. NOT all days are your "select members" ever going active, some days they won't be on for GNW. You lose some days when people start crossing the 35-40k power marks. Someone in our server called himself "elite", limited his number of members, and every GNW, this elite player get stomped. So much for self proclamations.

If your group doesn't mind losing some GNW, then by all means, go be an "elite" group. If your main players start quitting, you'll only have yourselves to blame; while the groups you defeat now will grow in numbers and power.

Edit: Our group has "open" recruitment setting. If your leader/senior/battle commander are wise enough, you would have zero problems with spies even with a 90+ members. We've been winning our GNW for months now.