The current system seems way to complicated, it either has the be a .xml pack to upload a group at a time or individual .png which takes a while given how many smilies you have. I think it should be simplified to where you upload them as a .png group and edit their 'activators'(:hi: etc.) from there.
I think that the announcement system is great already, don't get me wrong, but I think that a small feature addition may make it better. The addition of an option when making it that allows people to reply to the announcement or not and count it as a post/topic.
Seeing that you either have to create an identical admin group or do it individual(which can be a pain sometimes), I think that adding your permission sets function to work as an ACP only function would be a great idea. That way you can create a set, lets say, Full Admin and Basic Admin. You can then edit the permissions with the easier setup and assign those admin permissions to users and it makes for an easier job if you have many groups accessing it and you want different access levels.