Even if it didn't crop pixels or draw limits on the editor, it would be nice if you could set a fixed width and all the characters' advance values were set to that width. So you declare that your font is fixed at, say, 7px wide, and all of the characters are set to an advance of 7px.
Also, I'd like to support what someone else said about turning on pay-what-you-want for this download. You've put an incredible amount of work into it, and you deserve to get paid, even if it's just a little bit here and there. I can't afford much, but I want to chip in, at least as a more emphatic way of saying you're doing a good job.