How long is reasonable to wait for reply from an editor? About 5 months ago I submitted a paper to a journal. The editors assigned a reviewer. In the meantime I sent a couple of revised versions, which did not help matters, but the editor ultimately wrote back and asked me to complete my revisions and re-submit the document. I did that within a couple of weeks. The editors did not acknowledge receipt of this submission, but I did not want to ask for one since I felt I had already been pestering them too much. A couple of weeks later, I notified the editors that I wanted to post a couple of graphs from the submitted paper on a blog, although I hoped to make it clear that only a very small component of the whole paper was being posted on the blog. The editors did not respond to this notification. More than two months went by after the re-submission, and I sent a message to the editor asking for a status update, just to be sure that the paper was still being considered and under review. It seemed to me that a very simple "yes, it is still being reviewed", or "no, we have considered your paper withdrawn and it is not being reviewed" or something like that, would suffice. About 10 more days passed with no response, and I thought I would telephone the editor with my question, on the off-chance that my emails were not getting through.  I left a message for him, and another week has gone by with no response. At what point do I take the non-response from the editor as a message that my paper is no longer under review and that I should re-submit it elsewhere? The journal is otherwise a reputable journal, and I would like my paper published there, but there are many others that interest me too.  I feel like I made a mess of the whole process, and am to be blamed for over-communication and confusion, but am I not owed the courtesy of a response from the editor?
There are good reasons to expect communication with an editor to be slower than many other e-mail exchanges. Editors are busy, especially since editing may be a minor but time consuming part of their job. And responding to questions from authors often involves contacting referees, who may in turn be unresponsive.

I'd say that it's reasonable to wait a couple of weeks for a response to a timely request for a status update (two months after a revision strikes me as a bit early---I'd expect it to take longer---but not unreasonably early to ask for a status update). If it gets lost (for instance, the editor is waiting for a response from the referee, and hasn't remembered to tell you that's what's happening), a polite reminder and a few days to another week or so of waiting might be appropriate. 

After that, though, you can rightly begin to worry that you aren't hearing back. If there are other editors, especially a chief editor, you can contact, I'd start there. I'd be very reluctant to unilaterally withdraw the paper, since that might cause complications if the editor returns and feels you resubmitted while it was still under consideration.  Before resorting to that, I'd try to talk to one or two senior people in the field for advice about the specific paper.

(Just to emphasize, I'm talking about communication with an editor about the status of a paper. Of course the refereeing process as a whole can take a year or more.)