Hey Al,
It's the best setup, I think... Three switches, one each for House and Engine, and a third for Parallel. Dead simple, only way to possibly screw up might be to forget to disable the Parallel connection, and no possibility of frying anything in the alternator...
The ON/OFF switches from Blue Seas are very nice, appear to be of excellent quality, and are much more compact than the older 3-ways I had from Guest...
best regards,
Jon