Redmine

Spent the last week reading Mastering Redmine cover to cover while following along in my local Redmine instance. Between that, google, and the Redmine FAQ and HowTos, I was able to answer about 95% of my own questions. Here are the ones that remain:

1. Is there a way to publish site-wide announcements? By announcements, I mean stuff like "added custom field" and "installed X plugin", not "site going down for maintenance at 11pm", so perhaps more like an administrator's blog. The one blog plugin I found is ancient.
2. Is there a way to disable modules across the whole site? I would like to install the DMSF plugin to replace the Documents and Files modules, but I see no way to prevent users from being able to enable those modules in their projects. I know I can modify role permissions to prevent them from being able to manage them, but that's just going to confuse and annoy them, since they can still turn them on despite not being able to use them.
3. Is there a way to make Project description a required field? I know how to do that for Issues, but not Projects.
4. Is there a correct way to modify the content on the home page? The list of tips are nice, but I'd rather move those into a wiki page and reserve the homepage for announcements and activity feeds, plus some links to helpful resources.
5. Is there a way to delete an entry in the list of Issue updates? For example, I updated an issue with a note and file attachment to try the feature out, and I was able to delete the attachment after, but not the update itself (or the second update resulting from deleting the attachment).

FYI-Using Redmine 2.4.2, though will probably upgrade to 2.5.0 when I get a chance.

PS-All in all, Redmine is pretty dang awesome.