Must have plugin for blog provider?

I have plan to be blog/CMS web provider in my country. (Power by WordPress and WPMUDEV). I just installed WordPress Multisite and install some plugin like Pro Site and I not sure i should install Membership plugin for sign up process?

Please recommend plug in that must have for blog provider like WorpdPress.com, Edublogs.org. This is some of my list.
- Pro Sites
- Automessage
- Domain Mapping
- Anti-Splog
- Blogs Directory
- Moderation
- Recent Posts
- Messaging
- Chat
- Default Theme
- Simple Sitemaps for Multisite
- Global Site Search
- Communities
- Avatars
- Terms Of Service
- Mass Email Sender