John wrote:

Is it possible to assign more than 3 email addresses to one contact?

Not to a single contact.

Often, I'll have a contact change jobs (new biz email address) or
move (new personal email address), so I need to add/replace email
addresses for the contact. The problem is if I replace email
addresses due to being limited to 3 addresses, I lose all links of
prior email correspondence to this contact. Is there a way to retain
the links to email addresses that are no longer active and must be
removed due to the 3 limit without manually linking all old emails
individually?

You could create a new, duplicate contact for that person and have three
more E-mail addresses available to you.
--
Brian Tillman