I don't really understand the concept of genoharmonic foods.  Does this mean that we should combine 2 foods together for better health?  

Some of my genoharmonic foods are neutrals, and some of my diamonds are not even on the genoharmonic food list. It confuses me as I don't know if I should go by diamond foods, or the genoharmonic food list.

Please see this thread on Geno Harmonic foods:

http://www.dadamo.com/cgi-bin/Blah/Blah.pl?b-xpress/m-1247966474/

whenever you are having any food listed on the left, try combining it if possible with one or more foods listed on the right.....

no rocket science, just making the best beneficial impact on your body combining those, even if they re only neutrals when eaten alone,
given the SWAMI settings you chose.