You can tackle this in a simple but effective way.
Your needs seems to be of typical mass customer interaction / employee interaction organization needs.
All your needs can be grouped into the following
1. Content Management System
2. Customer Relationship Management
3. Accounting
4. Knowledge / Document Management System
5. Miscellaneous Requirements

I take a hypothetical situation of a solution using Open Source Technologies but you can substitute all of these with commercial systems.

1. Content Management System can handle your features of forums, news, calendar for training, team events and notices.
Add some forms to collect data and ability to publish articles.
Develop a point system as an extension to this. Look at Joomla CMS and its many extensions. So this provides a basic framework for you to present your organization to the outside world. http://www.joomla.org

2. Customer Relationship Management :
An open source CRM like SugarCRM provides Contacts / Accounts Management System where in all your customers, leads and opportunities, email campains can be managed effectively. It also facilitates to capture your employee information activities and roles etc etc.
Now the forms which are there on the CMS can directly be put into the CRM automatically as mails and processed.
You can also integrate your Accounting System like Quick Books with some kind of custom development.
http://www.sugarcrm.com

3. Accounting:
You can look at any of the web based accounting system for this. Something like Quick Books which is paid comes to my mind.

4. Knowledge Management:
The best open source knowledge management system which helps in managing and maintaining your documents is KnowledgeTree. There is already a module for SugarCRM to integrated KnowledgeTree called Zuckerdocs. So this helps to manage all your documents with in the system. It provides all kinds of restrictions based on roles for accessing, editing and deleting this knowledge. By the way SugarCRM provides even handling your mails from its iterface.
http://www.knowledgetree.com/

5. Any other custom requirements have to be handled by customizing the above or developing them separately.

All the above mentioned products comes with enough documentation for customizing and have huge list of users participating in their forums.

I am not too sure whether I have made this answer too long but I feel you are trying to put too many things into your knowledge management system. A careful analysis and planning is necessary

Ram Kumar
http://www.rheakt.com
References :

http://dir.wolfram.org/learning_management_systems.html

http://www.edutech.ch/lms/ev2.php

http://www.brandon-hall.com/solutions/lms_central.shtml

Good luck….
References :