I will bet you those quotation marks are not really a " or '. If you look closely at them, they are probably a bit more rounded. This is normall caused by the rich text editor found in a word processor. For the life of me I cannot remember what those are called.
Yup -- when I copied and pasted the text from the stream, it was not question marks -- but funny little boxes. I've seen them before over the years, often when someone creates a post for a forum like this in a word processor and pastes it into the forum's text box.
Question is, how to prevent it? Probably has to come from a bug fix at your end, looking for certain characters or ascii codes and converting them back to single and double quote marks.
So, with help I solved the centered text, and figured out the image layout on my own, and I have to assume you're working on the bug that puts the wrong characters into a post when emailed. That leaves (at this time) only the idea of having a subscription link in the stream itself, and possibly the idea of allowing limited comments -- sort of like Facebook comments. I also came up with another idea -- having a counter somewhere in the stream so I can see if anyone is actually reading it.