Yes. Publisher policies and practices within disciplines do vary, but recent surveys of journal editors showed that about 80% or more of journal editors in the sciences and the humanities and social sciences would "always welcome" article submissions based on open access ETD's, or would consider them on a case by case basis or if they were "substantially different" from them. A similar proportion of university presses surveyed would consider publishing a book based on one. In part, this is because most publishers consider theses and dissertations to be "student work" that will require substantial editing and revision before being published in article or book form. Publishers say that they are more interested in the quality of the work and an author's willingness to edit as needed than they are in whether the work has previously appeared in another form
The first thing is to check SHERPA/RoMEO to see what your journal's self-archiving policy is. If they allow self-archiving, you're all set. If they don't have a policy explicitly allowing self-archiving or sharing, it's important that your editor be aware that your work is part of your ETD and will be openly available if it is not already. In most cases, editors are completely fine with an ETD being available online. In some cases, an editor may ask you to adjust your access levels so that open access is delayed.
It depends. Assuming that you conveyed the copyright of your work to the publisher you need to see if the publisher allows it.
SHERPA/RoMEO is a good starting point for finding your publisher's policy. Alternately, simply google '[Your publisher] self archiving policy" or "[Your publisher] sharing policy."
As of Fall 2011 most major publishers indicated on their web pages that a previously published article could be included in a thesis or dissertation. If they do not allow it, you'll need to get special permission.
You will need to contact the editor you worked with to publish your work. If you don't have their contact information, you can contact the publisher directly. A draft permissions letter is available from ProQuest on pages 3 and 4. Contact library staff to determine the publisher of a journal and obtain contact information.
The second section of all theses and dissertations is required to be a Copyright Page that follows the Graduate School's formatting requirements. If you have transferred copyright to any part of your thesis you need to identify the correct rights holder on this page. Check with your department to see if they have guidelines on how this should be structured. If they do not, one way to do this is to identify each section's rights holder individually, and then state that you retain copyright to 'All other materials', such as the following:
Chapter 1 © Copyright 2016
Springer Nature
Chapter 2 © Copyright 2017
American Historical Review
All other materials © Copyright 2018
Jane Student