Independent of comparisons of recent activity of particular people -- in most cases, people elected for a public office serve a certain term of office, after which new elections are being held. -- Why should moderators on MathOverflow be an exception to this?

In my opinion, such maintenance edits to improve the quality of old posts should always be welcomed. The number of bumps to the front page is not much of an issue if you watch particular tags, or if you only look at new questions and then 'favorite' those you want to keep track of. -- Looking at the 'active' tab on the page with all questions is anyway only something for people who do not mind watching a really busy list.

As I understand, part of the reason why big-list and soft questions are usually made CW on MO is that one wants to avoid that asking and answering popular soft questions becomes the by far easiest way to quickly and easily gather a lot of points.

I think that the question you refer to is of "big-list" type, regardless of details of the formulation. -- The only sensible answers to the question are examples of where incorrect notation has led to mistaken proofs -- a negative answer cannot possibly be given. -- Hence I agree with Todd Trimble that the question should be CW.

@MartinSleziak: According to the migration statistics, in the last 90 days, 39 questions have been migrated to math.se, six to stats.se, two to scicomp.se and one each to mo-meta, to dsp.se and to hsm.se. This suggests that migration to targets other than math.se and stats.se happens pretty rarely, and can well be done via flags for moderator attention.

As 'proofs' is kind of a meta tag which is not used so frequently that its removal would be impractical, I'd suggest to remove that tag.

Videos are not an area in mathematics -- so this would be a meta-tag like reference-request. As I understand, the number of meta-tags should be limited.

@R.vanDobbendeBruyn: As to migration, I think it is easy enough for the OP to paste their question into a question box at the other site themselves -- that way they get a fresh question there which gets better visibility in general. Thus on the side of MO, it would suffice to close the question, and to suggest (a) site(s) where to post it instead -- and leave the choice to the OP.

Rather, wouldn't it be enough to have two close reasons "off-topic" and "no longer relevant" -- where closing a question as "off-topic" deletes existing answers and adds a message like "This question does not appear to be a good fit for this site in its present form. If it can be changed in order to make it suitable for this site, you might find relevant advice in the comments.", and closing a question as "no longer relevant" adds a message like "This question has run its course, and does not accept further answers."?

Isn't the underlying problem rather academic misconduct than a copyright violation? -- While copyright comes into play when actual text is copied, copyright does not prevent stealing mathematical ideas. That means, copyright merely forces the offender to formulate the proofs etc. in their own words, not more -- or am I mistaken?

@GilKalai: I haven't been involved with this so far, but I think here deletion was the way to go. -- I think the valuable questions for MO are those which are (largely) uncontroversial. Keeping questions up which stir a lot of controversy causes a lot of noise without much benefit for anyone.

I think the choice between the close reasons only matters when you vote to close -- when you flag for closure, then in both cases the question enters the close votes review queue, and in both cases it merely reads there "This question has been flagged as: off-topic" -- regardless of which off-topic reason has been chosen by the flagger.

(cont.): such payments independent from the decision to accept an article. Also, who would pay possible article processing charges for authors based in low-income countries, or for authors who are not affilitated with an institution? -- In my opinion, it would be best to make scientific publications exempt from copyright altogether (just as any type of documents where the copyright protection serves the only purpose to feed a publisher, and the benefit for the author is typically equal to zero).

@Lucia: Why do you think that the recommendations seem superfluous for math journals? -- I don't think they are -- also in mathematics there appear to be more and more journals where the peer-review doesn't work as it should (arbitrary-chosen example), and also in mathematics it happens at times that referee's reports lack professionality (personal attacks on authors and the like). -- What I find objectionable in the statement is though the idea of per-article payments to 'fund' open-access -- it simply doesn't seem realistic to me to make (continued) --

At least things seem to be a tiny(!) bit better now than they were two years ago.