Allow unique "Update Action" settings per item type (node, taxonomy,etc) or item (eg. page, story, vocabulary, etc)

Hello!

I've been working on a patch to clean up what I feel is some confusing behaviour re: the pathauto_update_action options in the admin and some of the associated UI. While I *thought* I was near completion, the more I looked the more questions started popped up. So I'm really hoping for some input here.

Currently, users have the following 4 options for pathauto_update_action (if they have path redirect also installed).

Update action: 

0 = Do nothing. Leave the old alias intact. 
1 = Create a new alias. Leave the existing alias functioning. 
2 = Create a new alias. Delete the old alias.
3 = Creat a new aliast. Redirect from old alias.

What should pathauto do when updating an existing <i>content item</i> which already has an alias?

So the big first question is: What is considered a "content item" ?

From the code, and experimentation, Pathauto currently considers a "content item" to be everything -- nodes, users and taxonomy aliases! Personally, I would think "content item" would just mean individual nodes though, for a couple reasons.

a) The core Drupal admin considers "Content items" to be individual nodes that are created.
b) I need it to be that way! :) Hehe..

But seriously, I don't think I'm alone here...

I'd like for existing node aliases to *not* be altered by node edits (especially for pages), but paths to users and taxonomy terms to always follow their current values. (ie. Fred changes his username to Freddy, I only want him at user/freddy now, and the same for taxonomy terms.)

I understand that others could have different requirements, but I think more flexibility and clarity would be useful to all.

Really I'd like to be able to set the "Update action" for nodes, users and taxonomy individually. (Ideally for each content type even -- I don't want my "pages" to ever move)

I'd like to get some of this in before an "official" Drupal 6 release of Pathauto, and I'm willing to do most of the legwork here submitting patch(es) if there is interest. I just don't want to end up with something that isn't useful/used in the end. I already do enough of that at my day job. :)