But then people won’t know it has been updated. And edits won’t trigger subscription notices either.
People use an RSS subscription to automatically track updates, rather than having a bookmark that they have to actively check all the time. Properly executed, you would be able to send update notices without the problems I listed above—the updates would be visible. And you would be able to make updates without having to worry about the necromancy/bump rules of this site.
Also, you could run it with a CMS that allows several other editors that could make updates to the main index. Currently, you are the only one that can edit the primary index in your posts (Mods and Admins notwithstanding). A shared site would allow you to share maintenance responsibilities with several others, which could be useful if, say, you wind up on an unplanned extended hiatus from this forum.
The primary disadvantage, of course, is that the thing is off-site. But then, the only practical effect that has that differs from this dropping off the front page here is that it won’t show up on GiantITP site-searches (including the Google site:giantitp.com style search).
On a gut level, I don’t particularly care for the off-site thing just because it is off-site. But perhaps the idea actually does have merit. Not like my gut is omniscient or anything.