Outlook conversation view and categories

At work, I tend to receive a couple of hundred emails a day. To keep from being overwhelmed, I have been using categories to sort and prioritize my mail messages. I auto-assign categories, then group by them: Code Reviews, To, CC, Distribution List/BCC. This means that, for example, a message that's explicitly to me will always show up higher in my inbox than one I get because I'm on a Distribution List. It's a huge time saver and it brings important emails to my attention much more quickly.

Recently, the email threads I'm involved in have started to get quite long, and I'd like to be able to use conversation view, or at least sort by subject. Outlook, however, doesn't seem to support any (useful) combination of conversation view and categories. I've tried the following things without success:

• Grouping by category, then conversation view — Outlook gives me an error (the grouping/sort combination is too complex).
• Using a custom view to group by conversation — category doesn't show up as an option to sort by
• Grouping by category, then subject — Getting closer, but the top subject is the first alphabetically, not the most recent
• Grouping by conversation, then category — This works, but it doesn't do me much good, because the top conversation is the latest, without regard to what category it belongs to

Is there a way for me to retain my category system or something similar while taking advantage of grouping related emails together? I don't at all care about the semantics of the solution, so I don't necessarily have to use Categories proper or Conversation View proper; I really just want to be able to use some kind of priority system to emphasize emails sent to me while having email threads grouped together in some way.

I've written Outlook plugins in the past, so even that's not too out there to serve as a proper solution. Anything that works, really.

Update:
I still haven't seen a good solution. I'd like everything to be in a single view. Separate folders or search folders aren't good, because, for example, if I've cleared out my TO list, I don't automatically see CCed emails at the top, I have to manually go to a different view for that. At that point, there's nothing to make TO inherently ordered before CC besides the order I click on the folders.

Being able to aggregate several folders/search folders into a single view would likely be a great solution. I haven't seen any answers even mentioning custom scripting/programming, and I suspect that any solution that fits my criteria would require it. The bounty is there because I'm pretty sure the solution isn't trivial.