Hi Chris - I got your email too and replied to that, but there are more details here that shed some light on the nuance of what you're trying to do.
To answer your question: no there isn't a way to force MarsEdit to publish all pending images to upload, but they always be uploaded automatically when you send to the blog -- whether it's as a draft or a published post.
So the nut of your issue seems to be that some of your images are not uploading correctly when you send to the blog. I don't think it has anything to do with the draft status or scheduling. If you create a dead-simple new post in MarsEdit, add one image, change it to Draft and publish, does the image not get uploaded there either?
I've gone back through the steps that I performed and I think I found the culprit.
Instead of publishing the draft (which I can confirm *does* post the images to the server) I took an existing draft and copy/pasted parts of it into new posts, so my workflow was more like this:
1. create local draft with pictures set to "upload with post" 2. copy parts of that draft (including links to pending images) into new posts 3. post those new posts to WP
Result: pictures in these new posts now stay pending, even when posted to WP
So I guess those pending images are directly linked to the according post and I ran into a corner case that you hadn't thought of yet.
Thanks for the info. Yes, indeed, I can see this screwing things up! Probably when a pending image is copied/pasted to a new post, it should generate a new "Upload" to go along with that new post. I'll add this to my list of things to try to refine in future updates.
I guess a workaround would've been to first publish the original post as Draft, which would have uploaded the images, and *then* split it out to several posts.
Yeah. It would be cool if MarsEdit were smart enough to see that a pending upload applies to more than one post and then go update all the drafts when it's uploaded, but currently things are more locked down to one pending upload is tied strongly to one post.