Thank you both for your help!
Well, such an approach will be very interesting for the new release of ojs and of course supporting BibTex references, as from my knowledge as a PhD student there are many professors which use LaTex and store their references in BibTex format.
As for adding new metadata fields in OJS, based on our librarians requests, we have a few.
The first, and I think the most easy, is to add a new field in submission process step 2. We would like to add a new field for author's full mail address (under affiliation).
The second , I think is more difficult, we would like to exclude the "add supplementary files" from the submission process and request the author to upload a list of supplementary files (which include figures, tables, some instructions is seperate documents) after review. This will be done in author's SubmissionReview page. (This is done mainly because the journals are from athropological sciences, specifically Greek history and culture, and, in these cases the workflow is a bit different. For example, the author must ask a museum the permission to publish a photo of an artifact and this is not done until the article has been accepted for publication.
I hope this helps...
Again many thanks for all the help and I am sorry for bothering you with all these questions.