Hi,
I did a change to lib.php in the tinymce editor folder which seems to be a solution for what I required.
Admin, Manager, teacher etc all get the full set of options. Students and guests can have a separate set of editor options which are controlled by the general settings for the editor. If it was required that a manager and a teacher have different options changing the code is simple.
One thing I found was that for the students to have access to the spell checker in the general settings you need 3 lines of options and the "code" keyword on the third line. This is not a problem with my coding, as it happens without it as well (just for your information).
All my changes are marked with the initials tjr, so a search will show the added bits.
Of course if you place this in your Moodle 2.4 system always have made a backup of the original file so you can restore it to its default state.
The file can be downloaded from http://tonyrogg.com/moodle2_4/lib.zip
Thanks,
tony