I say for simplities sake you stilck with what you said on;
4. Teams are not integrated. You may not share tech (for example, using each others teleport homers, etc).
5. If a unit/wargear/ability says something to the effect of "choose a friendly unit/model" you may not select a teammates unit.
So best thing to do would probably say going forward all spells and special rules only afftect the army casting it, period, no exceptions. That prevents vulkan/sisters tervigons casting FNP on its partners bugs, etc.