Hi Andrew,
The jQuery widgets are wired up with a small bit of javascript added to the page by our ScriptLoader
<script type="text/javascript" > $('div.mojo-accordion').accordion(); $('div.mojo-accordion-nh').accordion({autoHeight: false}); $('div.mojo-tabs').tabs(); </script>
If you need to wire up additional widgets you could make your own custom script loader control and add it to your layout.master file or you could directly add initialization script at the bottom of layout.master
We don't currently have import/export of content templates and styles but it has been requested and will eventually be implemented, it isn't a top priority though.
The icons for feature instances are only used in the MyPage feature when you make a content instance available to MyPage then the icon is shown in the web part catalog where you can add content to MyPage.
I will put it on my to do list to make it possible to make the newsletter send task have a setting that can make it throttle how fast email is sent or pause in between sending them or something similar.
Best,
Joe