to work around the format issue, maybe it could be something modular similar to the way the observation fields are, where a field can be added as a block to the identification page? this could apply to tables and graphics as well, if someone were willing to code that into the site ;P since iNat uses wikipedia articles for the main organism pages, I’ve slowly been creating wiki pages for taxa I feel are important and lack useful information, especially with papers and databases not being readily accessible to most yet. that seems to at least somewhat work around it—journal entries as you highlighted are another great alternative, where experts can share their expertise. I think it would be cool if journal entries could be highlighted and attached to taxon pages where they are displayed clearly enough that they can’t be missed.
all in all, I agree that there is a lack of a wiki-like part of iNat which is a major drawback, but implementing that alone could have its own complications. maybe developing a pre-existing feature such as the journals or wikipedia links (add support for linking BugGuide info pages through links so wikipedia isn’t the only source?) would be a good way to address this.