Font size can be done by using the pre settings of Format (blocks) however few....
It all comes down to license (adv. editor etc..),
E107 uses the available free (open sourced) TinyMce pieces. (CE ??)
Some items are no longer available without additional possibilties ( aka licenses and $$ ).
A better understanding you will get visiting tinymce Community edition vs Premium.
In the older 0.7/1.0 version (tiny 3) more was possible, newer (bs time) things shifted to premium.