1. If DOI is activated in the setup does it get allocated to everything e.g. forewords and afterwords as well as articles?
Forewards and afterwards are sections in your journal? If so, yes. In our journal, jima.imana.org, everything which appears in our table of contents gets a DOI when I do a DOI export. Perhaps, Home > User > Journal Management > Journal Sections > Section should allow disabling of DOI assignment for specific sections.2. At what point is the DOI generated for a particular paper ?
In Home > User > Journal Management > Journal Setup Step 1.1, you determine how your DOIs are calculated. DOIs only become live after submission to your DOI assignment agency. In the US, for example, that is crossref.org.3. Where can I find the DOI for each paper once it has been generated (I have all permissions except systems admin)?
see question 2. In our case, we generate the DOI through [prefix]/[volume number]-[issue number]-[OJS article ID]. So I know the DOI as soon as I submit a manuscript and assign it to be published in a specific volume and issue. Of course, if I i'm uploading articles to back issues, I know what the DOI will be as soon as OJS assigns it an article ID.4. Currently the editions of IJEA have all comprised conference papers so we have not been using the full functionality of OJS - the papers get emailed to me and when they are ready I upload them as final pdfs using the QuickSubmit plugin. Clearly this will need to change if we decide to use DOI as CrossRef requires the DOI info to be included on the paper itself. Depending on what the answers are to questions 2 and 3 has anybody got any suggestions as to what I would need to do in future (I am hoping that I will still be use the plugin but perhaps in a slightly different way)?
What I'm doing with our journal's back issues is using a full version of Adobe Acrobat to add, using the typewriter tool and the linking tool, the DOIs to the first page of each article. This is significant work, but it is even more significant work to add the DOIs for the references (CrossRef's forward linking).5. I note that some code has been supplied to get the DOI to display in abstracts. If DOIs are also generated for e.g. forewords where does this display appear (if anywhere) given we have chosen for these not to have abstracts?
Even if a section does not require abstracts, you can add an abstract. I just write
in the abstract in OJS.