Great set of questions.  I wonder, though, if other states have the variety of surveys and township sizes that Ohio has.  My general understanding is that we are somewhat unique in this area.  You can go to http://anderson.mine.nu/Anderson_geneology/land_survey_definitions.htm#Top
to see the variety of surveys that are not section/range dependent in our state.  I believe these variances run into eastern Indiana and northern Kentucky.  My home county is about half sectional and half Virginia Military Distict.
I would change the questions regarding Deed of Trust to read Deed of Trust/Mortgage in order to clarify for those in a fee state as apposed to a lien state.