[Rover] External Battery Power in a 2011 Honda Pilot Questions for my Rover

[Austin]

For the contest next weekend I will be running about 6 radios and 4
Amplifiers.  On transmit the amplifiers draw 35-40 amps and the radios
add 10-20 additional amps.  I can not rule out that occasionally two
amplifiers will be keyed simultaneously for brief seconds.  For that
reason, I have purchased two Optima D31T Batteries.  I want to put them
in parallel (Let's call them Battery A and B).

On the back of my 2011 Honda Pilot, I have the factory Trailer Harness
installed.  It has a 7-prong Outlet at the hitch.  According to the
manual, there is a Charge post and a Ground post.  Supposedly this is
used to charge batteries in a small RV.

Here is what I am thinking.  A and B are connected directly to one
another in parallel.  All of the radios and amps are connected via
Anderson Poles and Power Splitters from West Mountain to Battery B. 
>From the Trailer Harness a power cable is run up into the cargo area
(fused and with an instant kill switch for safety). 

Question #1 - Can I connect the power cables directly to Battery A?  I
realize that this is elementary electronics question but in this
configuration will the radios and amps get their power directly from the
batteries, or will it try to pull the full power from the cable coming
from the Trailer Harness?  I ask because I don't want to vaporize the
factory wiring in the vehicle.

Question #2 - I also purchased a West Mountain ISOPower unit.  It has
three posts on it (A- Car Battery, B- Radios, C- Spare Battery).  It
also has 40 amp fuses between the posts.  Because of my power
requirements I was thinking about connecting the Trailer Harness to Post
A, leave post B empty, and connect Post C to Battery A.  In this case,
Battery A is still in Parallel with Battery B, and all equipment is
connected to Battery B.  I heard a rumor that when the Trailer Harness
is installed, Honda puts in an Isolation Circuit to protect the car
electrical system, and that I will cause problems if I put two Isolation
circuits together.  Is this right?  

Question #3 - Is there something else that I should be using to
accomplish what I am trying to do here?  Basically I want to run
everything off of the battery bank, but use the car power to charge the
batteries in between transmitting.

Question #4 - With the above configurations, do I still connect all of
the ground plugs from the radios and amps to the frame of the vehicle?

The contest is Saturday and I am in desperate need of guidance.  If
there is something that I need to get on order, I need to do so by
Tuesday or Wednesday to get it here in time for the contest.  I
apologize for asking such elementary questions, but I don't have any
"elmers" here and I really don't want to damage my very brand new Honda
Pilot.

Any guidance is greatly appreciated.

73,

Austin
k4amk/r

NOTE:  Rover plans will be posted in the next few days!!