Your comments

I use the apple bluetooth keyboard, which has all* the characters in the special characters bar, but I'd still like the option to leave the bar up for convenience.

*except what windows users would call the delete key
Workaround: DROPBOX!
It can upload files from photos, then Textastic can download from dropbox and re-up to the (S)FTP server.
+1. So far, the only way I can see to do this is to email it to myself and then import it from email, but my email app isn't showing the open with dialog for the photo ... so I'm back to square 1.

I think I'm going to have to put it on my computer and upload it from there. Can't find any workaround that I can do from the iPad itself...