1) Passers-on
As they are already well networked and interconnected "Passers-on" receive a lot of messages and see many sites. They redistribute and send out much of what they find and repute interesting, humorous, and of possible interest to others.
(Comment: Passover happens to be a religious feast of our Jewish sisters and brothers, so I wouldn't use the word to describe an individual engaged in passing on information. A suggestion would be "Passers-on" similar to the term passers-by, which actually does exist in English)

2) Filterers
Filterers are Passers-on with a specific interest. They pre-filter and select interesting info bits to be spread to a limited community of like-minded people. Such mini-networks brought to life by one individual do not ususally go beyond 150 people.
(Comment: changed to passers-on and added "brought to life by one individual")

3) Hunters
Hunters go out proactively to search information and new resources by investing systematic time in this effort. Hunters have all the qualities and virtues of Passers-on and Filterers while integrating good search, synthesis and summarization skills.
(Comment: changed to passers-on and added another "er" to Filters)

4) Publishers
Publishers pick out the best that Hunters provide and post, email and publish online on their Web sites key information items, stories and resources that are of value and complement to their own mission or to the purpose of their network of interest.
(Comment: changed "one" to "purpose" to make reading more fluent)

5) Aggregators
Aggregators harmonize complementary resources, tools, ideas, and actual content to create:
a) easier access to specialized knowledge
b) mini-guides, tutorials, dossiers and reports on specific topics
c) specialized knowledgebases and directories

6) Independent Reporters
Reporters make a living off the Publisher role and take on specialized research, investigative and reporting skills. Reporters create their own magazines, newsletters, reports, books, audiotapes and videos. They participate in workshops and conferences and take a very active role in educating and explaining information in their areas of expertise.
(Comment: changed of to off - better grammatically)

7) Communic-action Agents
Communication Agents understand the overall communication process at work on this planet. They have long studied and invested extensive personal time, passion and resources to play, tinker, experiment and discover which tools, methods and tactics provide the most efficient, speediest and widest effects.
Communication Agents understand that they hold digital weapons with which they can peacefully overcome apparently much larger and resisting forces.
(Comment: changed bigger to larger for grammatic reasons. Communic-action Agents seems awkward to read and I notice that in the text you use Communication Agents. I think this latter term is better and more easily understood.

Where do you fit?

At what level are you?

(Comment: for myself, I do some of the things described, but could not limit myself to only one of the categories. It's kind of a gradient. Once you learn one area, the one that attracts you most, then you are free to start in on others. I suppose it's a learning process.)

Do you see gaps? Can you suggest improvements?

"Knowledge defends you against every form of harm in existence.
If you think of the word knowledge what kind of boundaries or limitations can you see it describe? Any?

(Comment: Yes, knowledge limits the otherwise quite normal stupidity and bumbling that is our way of going through life)

If so, what do you think is the value of that word (knowledge)?

(Comment: The word itself is without value. the thing it describes is what we should be striving for because it does, indeed, tend to protect its bearer from harm and what's more - ultimately it has rewards better than the best movie or the sweetest tiramisu...)