Готини плъгини за  WordPress Multisite е:

1. Multisite Plugin Manager
2. Hyper Cache Extended . Подкрепете Българаското. На адаша Мартин!
3. Diamond MultiSite Widgets
4. All in One SEO Pack
5. Akismet
6. Yet Another Related Posts Plugin
7. SEO Smart Links

За наспамени блогове от коментари могат да се премахнат лесно така:

delete from zna_comments where comment_approved!=1;
delete from zna_1_comments where comment_approved!=1;
delete from zna_2_comments where comment_approved!=1;
delete from zna_3_comments where comment_approved!=1;
…

Ако ПРЕКАЛЕНО много са наспамени т.е. 100% така:
delete from wp_comments;
delete from zna_1_comments;
delete from zna_2_comments;
delete from zna_3_comments;