Abbreviations reminder, just in case: DV = downvote, VTC/VTD = vote to close/delete, LQP = low quality posts.
First, as Kevin pointed out in a comment, there are a couple of reasons to edit off-topic questions.
Removing or fixing bad tags.
In case the post later gets edited in an on-topic, non-dupe question, the tags will already be sorted out. It's a good thing. Plus, people watching said tags might be more likely to eyeball the question and provide guidance on how to reword it into a good post.
Removing personal information (e.g. "Please email me the answer at [email protected]").
That one doesn't need any explanation, although IMO, if you're going to edit out personal information, I'd say to also flag it for a mod to mod-delete the mail/phone number/etc out of the revision history; they have a tool for that.
They did not agree with you that the questions were blatantly off-topic, and felt they might be salvageable.
If you can think of a way to salvage a question, an edit is welcome. If it looks like you've strayed off from OP's intentions, add a comment for OP stating why you did it (making it on-topic), and that they're free to revert the edit. It might then be closed again, but they'll have been warned. Couple of recently savaged questions:
Fixing severe formatting problems that made the questions difficult to read (so that other high-rep users could more easily see their off-topicness).
That's also a fair point, not much to add here.
Now about the three specific ones from yesterday.
Star Wars fight question
The timeline of "Star Wars fight question" shows that the edit was made through LQP review queue. It's not obvious, but editing through the review queues kicks the post off said queue (per main Meta). It's not obvious, because in Low Quality Review, you're faced with 4 buttons: Looks Ok, Edit, Close (on questions)/Delete (on answers), Skip.
The screenshot below is a bit outdated but it shows the gist of it:
Nowhere does it explicitly say your edit will remove it from queue. It looks like the ordinary Edit button. So if you're not sure it should be closed, but still think it's worth an edit, there's an Edit button right here rather than the skip/close ones. Flaw in the system if you ask me, that should read "Edit - warning, it's a binding out-of-review edit". But I digress...
Star Wars Midichlorian counts
The edit made the question go from "unreadable block of text" to "readable off-topic list" (compare). Is the question still off-topic? Very definitely so. Is it clearer why? Kinda. The block of text screams "unclear" before it screams "off-topic", but a post that opens with "What do you guys think of my list" is explictly a no-no per the Help Center's "Don't Ask" ("there is no actual problem to be solved: “I’m curious if other people feel like I do.”").
It's not the greatest edit you'll find in this site, but at least it doesn't disturb the homepage as the question scored below -4 (and thus is only bumped in the "active" tab, not on the homepage).
Did I find Middle Earth?
The edit (screenshot) fixed a bit of formatting and added the j-r-r-tolkien tag. Once again, it's not the most useful edit in the history of SFF, but a j-r-r-tolkien watcher might be able to provide more guidance (see point 4. above) or actually understand what is going on here. The question was deleted shortly afterwards, though.
About editing "on hold"/dupe questions...
Of course, it can happen that one has just woken up/is on their phone/just isn't giving it much attention, so they go for an edit instead of VTCing/VTDing first. Happens, fortunately we have a good base of other users who moderate the site and take care of the matter. Sometimes people can also think twice and VTC/VTD something they didn't deem worthy of before.
Coincidentally, it happens that when an "on hold"/freshly dupe-closed question is edited, it automatically gets sent to the Reopen review queue, where anyone over 3k rep can vote to Reopen or Leave Closed. That includes the one who edited, unlike, for instance, VLQ posts that you can't review if you previously cast a VLQ flag on them.
As long as the edit somehow helps the post with regards to 1+ of the 4 points above... It kind of helps, even if by a long stretch, so, alright, I guess.
However, in my only-commits-me opinion, when you're going to edit off-topic questions with a very minor edit, and then cash in a Leave Closed vote (progress towards Reviewer/Steward badges...), and then vote to delete it right after that, repeatedly, perhaps the "Delete" button is the first one you should have pressed. Just saying.