Joe -
Q1: (From 2003 UL 'white book', pg. 21, Conduit Fittings [DWTT]) - 'This category covers metallic....conduit fittings, such as ... conduit bodies...'...towards to bottom of pg. 21, right column is the heading "Grounding" - "All metal fittings for metal cable, conduit and tubing are considered suitable for gounding for use in circuits over and under 250v...". - to answer your question, it looks like UL accepts metal conduit bodies as a satisfactory grounding means. [Soares does a number of tests with conduit fittings but I don't see any testing of conduit bodies].
Q2: ?... if the RMC is threaded properly (346-8) and 'made up tight' as required, it seems to me you'd have the 5 threads engaged regardless of location.
Q3: using the term 'equipment bonding conductor' does seem to help some folks better understand the function of this conductor.
Q4: 200' of pipe and fittings...see Q1.
