Sometimes I come across an image and am not sure if it is tagged or rated correctly or some such. At the same time, I don't really wish to put forth the effort to find out, and I don't want to change it if I'm not sure.

For example; #2812441 - this has the Group tag, but all but two of the individuals are corpses and not participating as anything other than set dressing. I don't think it counts as a 'group', but since there are a half-dozen other bodies in the video I'm not certain enough to change it. I'm also not concerned enough by it to go on the Discord and hash it out, but I am a little interested in having it resolved.

I could mention this in the comments and hope someone more educated or dedicated finds it, but that's unreliable - and not something that would-be tag crusaders can really search for.

My suggestion; on Wikipedia, every article has a Discussion page where people can talk about potential edits and other issues without committing a change to the article. I think the posts on e621 should have a similar page. I'd just click a link for 'discussion' and post there that I don't think this is a group & why. Other users can then search for new or open discussions and take action as they see fit. Perhaps I could even be notified of any responses and the discussion could be 'closed' by myself, a moderator, or after a certain time period has passed - to keep from cluttering up the list of open discussions.

I'd post my concern to the discussion page, some other user would look at it and respond, and either change it themselves or not, and I'd get a message. From there I could act on the other user's advice as appropriate and close the discussion when I am satisfied; or be a slob and let it close itself in 60 or 90 or whatever days.

If this feature was implemented, a further use of it could be to lock or block certain tags for the post; if something is contentious to the general population and gets bounced back and forth, a proper discussion could settle the matter permanently. This would be a more advanced feature and need policed by the mods; a normal user like me should at best be allowed to suggest a lock/block when I close the ticket and the actual application of said action is decided and performed by someone relevant.

We really do not need two separate comments section for each and every single post, just for the sake of tag change discussions.

If you are unsure about something, take the initiative to look up the forums or wiki for clues, ask in the comments (for newer posts) or the forums itself (for older/less visible posts), or engage with the help-desk on Discord (for fastest response time).
If you can't be bothered with any of that, you can just change the tag by yourself and include your reasoning in the "Edit Reason" field before submitting it (e.g., "I'm pretty sure corpses are not considered as part of group."). Then, if anybody disagrees with your tag change, they can respond in kind with their own tag change and edit reason (e.g., "No, I believe group consists of ...").

Contentious tag edits (i.e., tag wars) would always be resolved by the final word from an admin, with the relevant tag locks made without much additional discussion.
This would, of course, require the post to be first reported by someone to notify the admins to make a final ruling.
On the rare occasion, you can also report the post if you feel that a locked tag is unjustified and a second opinion would be given by another admin.

As for post #2812441, I would say that duo would be better than the group + duo_focus combo, as the corpses are not active participants in the post. It would be if they were surrounding them and/or walking about in the background.

thegreatwolfgang said:
take the initiative

That's the thing, though. I really don't have the initiative a lot of the time; this is a commitment of a decent amount of time and energy. As it stands, if I see something, my options are:
1) Spend a bunch of personal effort.
2) Shot in the dark.
3) Do nothing.

Option one isn't something everyone can just do casually. While I appreciate the people who spend all day on here cleaning things up, I don't have it in me to be one of those people. I can't drop what I'm doing and research every issue I see.
Option two is no good. If I'm wrong, I'm not doing the site and its users any favors, and if I keep getting my tags reverted I'm going to start getting negative feedback. Again. In the best case scenario, I still need to come back and see if someone edited it and see if they bothered to put a reason why, otherwise I'll keep making the same mistakes, so it's still a fair bit of effort on my part.
Option three is one I definitely have time for, but it does what it says; nothing. If I just let it go, nothing happens until some other random person with more ability to correct it comes by.

Option two is not a happy medium between one and three, it is essentially going off half-cocked to make changes that might be correct; throwing shit and seeing if it sticks. This isn't a good way to do things and shouldn't be encouraged to the general user base.

The discussion page does function as a healthy compromise. It allows me, as the casual user, to flag something for the attention of more dedicated volunteers. The people that do want to be on here all day, whom I deeply appreciate, can have a means to draw their attention to the issue. This will save them time compared to combing entries at random looking for possible errors; they can log in and see a list of possible errors put up by casual users like me. Instead of half-assing the situation or doing nothing, I've passed the ball to someone who can handle it and the problem gets fixed correctly.

The Discussion Page would let casual and dedicated users work together to make sure things are done, and done right.