The following issue summaries were written by Robert Diehl as a part of Chronology.Net. This information is not to be reproduced without permission of the author.

The Confusion of Names:

James MacDonald Hudson is called James, Jim, Jimmy, Jamie, Mac, Hudson, Weapon Alpha, Vindicator, Guardian, or Antiguard, depending on the speaker and timeframe.
       Heather McNeil Hudson becomes Guardian in iss. 32, but on the cover is referred to as Vindicator, which name she adopts in iss. 34, until she takes the name Guardian in iss. 90, when Mac returns as Vindicator. Her family name is sometimes spelled MacNeil.
       Snowbird's real name is Narya, but she had an identity as Corp. Anne McKenzie, RCMP, and becomes Mrs. Douglas Thompson in iss. 34. Walter Langkowski is Sasquatch, but so is Tanaraq, and so is Snowbird, when she wants to be, but her sasquatch is albino and female, and Walter possessed that body in iss. 46-68 and was Wanda. Box is originally Roger Bochs, but is sometimes Walter and is taken over by Madison Jeffries in iss. 48. Jeanne-Marie Beaubier is Aurora, but the two names usually refer to separate personalities.
       Jean-Paul Beaubier is Northstar, but he had been known as Jean-Paul Martin before he was reunited with his sister. Madison Jeffries's first name is not revealed until he joins the team in iss. 30. He is not to be confused with his brother Dr. Lionel Jeffries (Scramble), who merges with Roger and becomes Omega. Michael Twoyoungmen is Shaman, and his daughter Elizabeth becomes Talisman, but then Michael is Talisman in iss. 38-68, until first Walter/Wanda and then Elizabeth take it back.
       Dr. Whitman Knapp is occasionally called William. His various personas have the code names Prime Unit, Proto, Apeman, and Highbrow (once Hybrow). Kara Killgrave is the Purple Girl until iss. 81, when she becomes Persuasion. Her father was Zebediah Killgrave, the Purple Man.
       Laura Dean and Goblyn are twin sisters. Laura is not given her codename Pathway until iss. 114, and Goblyn was never given a civilian name.
       Kyle Gibney is Wild Child until iss. 102, when he returns as Weapon Omega, not to be confused with Weapon Alpha or Weapon X (which name was first given to Logan, then Garrison Kane), or Omega (the merger of Scramble and Roger Bochs), or Omega Red (the Soviet super villain), or either Omega Flight, although he had been a member of the first Omega Flight. He becomes Wildheart in iss. 118. His last name was never revealed in the pages of Alpha Flight.
       Albert Louis is not given his codename Feedback until he joins the team in iss. 126, so he is a superhero for all of 5 issues.

Disclaimer: I have never seen a series with so many flashbacks! I have tried to catalogue all the characters shown, but have doubtlessly missed some. Mac, in particular, does much more in flashback than real-time.