Ashley - Why can't you create new Action Sets? For me, you just go to the big Infusionsoft tab at the top, scroll over it, and select "Settings" from under the Marketing column. You should see Action Sets in the left-hand column after clicking that, and you can add new sets through there. Is that not an option for you? If not, you may not have a complete set of user permissions in your application.
Emily - All I can tell you is that there is a report submitted with them about the issue. I don't why it happened the way that it did. If you want to do something, contact Infusion's help chat and discuss the issue with them - then ask them to file a request about the function. The more of those requests we make, the more likely we get a quick fix.
Another overall fix would be to redesign your letters to compensate for the altered margins. I know it's not the same, but it would allow for a more seamless process. I guess it's weighing the look and feel versus the efficiency. I'm not making a value judgement for anyone - after all, we're still mostly doing Letters manually on our end (basically with Emily's workaround). But if you're doing heavy volume, it might be worth just building a new letter and accept the increased margins.