What figure formatting can, should, or will be done by a publisher? Background
When preparing a final version of a figure, it appears that some changes could be more easily made in a graphics software (gimp, inkscape, scribus, adobe) as opposed to R. Such changes might be done more efficiently, and more to the publishers standards, by the publisher. Apparently, the publisher uses some such software to makes final changes to the image anyway. Presumably, these changes can do it more efficiently and to their standards. Also, some tasks would be trivial or would be done anyway by the publisher.
Some tasks that I am currently doing to prepare figures for a journal article:

move / add text
change font
change line thickness
change background color

Something that would be neat to do:

integrate figures into text, in the style of Tufte:



Questions:

What formatting is commonly done by a publisher rather than an author?
Is it reasonable to make requests?
If so, what work will a publisher be willing to do?
For many years, the standard on the part of journals is to do absolutely nothing with respect to journal articles. Essentially all of the work in terms of preparation falls on the authors. Previously, figures had to be "camera-ready"; now, they "just" have to be publication quality. The journal production staff will not do anything, except potentially change the size of the graphic to better fit the column space.

You should check with the journal about the regulations on acceptable graphics; they should have them available for your review on their website. If there are questions about the use of graphics outside of those guidelines, send an email to the journal office.