I think it's a good idea because it's an idea I had a while back. I just didn't have the ambition to actually follow it up.
I don't think dividing the codex into annual parts will be that big of a hindrance. Once a Google spider crawls through it, it'll remember where the keywords are. And even searching each page manually won't take that long if you put links to the previous and next page like you do with the comic. (One request though - if you do that, put links at both the top and bottom of the page, please. Scrolling back to the top of a page to hit the next link gets old.) If the number of parts still seems too unwieldy, 2- or 3-year sections shouldn't be too big.
As for dialogue, somebody with more time than either of us might be able to OCR the strips. It looks like you went to adding text on the computer pretty early. (Either that or your lettering improved a LOT in the space of a day or two.) Having a consistent typeface helps a lot. The resulting text would still need a lot of cleaning up though.