It's also that fact that everything has to be a hedge. You can't simply say, "My original research results show that stimulus A causes response B with p<0.5, and this is what I did". The first problem with that sentence is that you have to be both original (work not done before) and not original (work based closely on work someone else has already published, or else it's too much of a leap). The second problem with that sentence is that you have to hedge, saying instead "seems to indicate", or "possibly blah blah". Also you are forced to spend more time explaining what other people have done with references, than explaining your own work. If it takes you more than a paragraph to explain your own work (which shouldn't have references, because it has to original right?) then you "don't have enough references" because every statement you make must be supported by a reference, never mind that the interesting statements are the stuff you shouldn't be able to to reference because it's new stuff.
Regarding word limits: instead of having a strict word limit of 2500 (for example), instead have a hard limit of 5000, and discounts for every hundred words below that, assuming the publishers are taking money to publish... sorry, silly me, of course they are
As far as your basic requirements are concerned, pretty much any major (git, svn, mercurial) open source version control system will cater for them, with some third party (mostly) free tools. Local server, well established, open source, email notification via hooks, extensive (if not easy to read) documentation
For your 'nice-to-haves'; you would be looking at a third party stack. I personally would recommend gitlab. It comes with baked in issue tracking, project wikis for documentation/planning, email notifications without you having to script hooks, LDAP/AD integration (iirc, never used it myself), merge/pull requests (i.e. a form of code review). You can attach/upload files of any type to issues/comments/wiki pages, not sure if that's what you are looking for. Alternatively, you could look at gitstack, which just fits into your price range and covers most of the maintenance/admin headaches by the looks of it. I've never used, found it by googling.
Finally, git (and possibly mercurial and svn) has a way to sign off commits using a GPG key. This work flow is also accessible through gitlab. Basically, a change is made and committed to branch which is then pushed to the gitlab server. This generates a pull request to some pre-designated branch (e.g. trunk/development/whatever). When the pull request is approved, it can be signed using the approver's GPG key. I'm not sure is this covers your specific use case; I'm afraid I'm not sure exactly what you want from the signing part of your requirements
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I mentioned the +/- zero thing in another comment elsewhere in this tree, actually! So we're all on board there.
It's not really that signless infinity is a contender for 'consensus' inasmuch as number systems which use signless infinity have utilities different from systems that have signed infinities, just like integer math continues to exist despite the 'improvements' of fractions and decimals.
The secret of success is sincerity. Once you can fake that, you've got it made. -- Jean Giraudoux