Lawrence,
  Ok - seeing the entire layout I can see the need for reversing.  Here is what I'd do.

  You have a left side and a right side - connected by the middle that has the
crossover in it.  One of the important things about the crossover is that you
have a green path and a yellow path - and it does not look like you would ever
want/need to run trains thru both colors ... at the same time.  So make that a
"rule" and wire accordingly - personally I'd wire it so that the green path and
the two turnouts on either end of it - is all treated as one logical section and 
that path is either not powered or fully powered.  Same for yellow.  I'm saying
that if -both- turnouts for green (or yellow) aren't thrown the entire "green route"
is unpowered.  And I'd set up the controls so that one DPDT sets the turnouts
and powers the track - center off DPDT - throw it one way and it throws both
turnouts and the track for that route, throw it the other way and it throws both
turnouts and powers the track for the other route (center off results in the
straight thru direction for all 4 turnouts and the routes and the crossover are
all dead).
  Finally as Don (?) suggests - I'd make the left side and the right side the
two reversing sections.
  I'm wording this rather clumsily ... but I think you understand what I'm saying.
The gaps and the controls will set it up so you can make it happen in a way
that works and your trains will run just fine.

  It is definitely a good idea to follow the rule of "the longest train has to be
shorter than your reversing section" and you can -only- break that rule if all
of the wheels of your train but not the locomotive(s) are non-conductive.  The
reason for this is that as a metal wheel crosses the gap it connects both
track segments (does not matter if gaps are not opposite each other).  And
when that happens you -will- get, at best, a 'stutter' as the train crosses that
gap (every metal wheel will short/want to reverse as it crosses the gap).  So
try to follow the 'rule' ... because you might run a train thru and it will work
but the next train or a train 2 years from now won't.

  BTW - neither the scale you are running nor the size of the layout make any
difference in how to wire a reversing section or crossovers.  But the brand of
track (including turnouts and crossovers) is something that can make a big
difference (but not usually/always).
                                                                                    - Jim