How can I link/share an email message to the workspace, calendar, lead(from more than 1 email add)?

How can I link/share an email message to the workspace, calendar, lead(from more than 1 email add)?

1. Share email to workspace. 
I have a workspace which is accessible to everybody in the team. It is organized with subfolders. I would also like to add a folder specifically to keep important FYI email messages for the team. So that everybody has an easy access to these important emails. At this time, the only way for me to do this is to convert the email message to a word document and upload to a subfolder, which is time consuming and tedious.

2. Share email to calendar.
 I find it also very helpful if I can link email messages to the calendar. For example, for a specific marked date in the calender, If i would be able to link email messages to that, I and the shared user will be able to check the status of the event anytime.

3. Share email to lead (if lead has more than 1 email address)
In the leads (my email sharing is configured), we have 2 fields for the email addresses. I noticed that it only links/shares the email messages generated from email add #1. Most of the time, I get messages from 2 or more email addresses for the same contact. For example, an email from the secretary, or the email of the higher ranking person who referred me to the lead contact person. I want all related email's reflect on that lead. I don't think its necessary that I create another lead item for the secretary just to keep track of her emails to me. 

4. More over, If my superior sent me an email message, concerning an existing lead or to create a new lead, it would be very helpful if i can link that email to that lead.  At this time, the solution for items number 3 and 4, is to copy and paste that email message to the notes.

I hope you can help me with these.. thanks