The summaries of all these studies can effectively be summarised as: if you are raising children on a vegan diet, ensure you supplement and have adequate calory intake. Taking datapoints from figures and graphs without understanding the underlying causes and effects is how we spread misinformation. It's great that studies are measuring this so that we understand better how humans can develop successfully.
An example of this is in study 6 where you stated that vegan children were shorter and weighed less. Whilst true the study also stated "The energy intake of the vegan children was consistently lower than the recommended daily amounts". It then concluded that with a sensibly planned diet vegan children should have no intellectual or physical problems in their development.
So whilst I agree that all the studies did find differences, I disagree that they are somehow proving against my points that a vegan diet in children can be healthy if correctly planned. Due to how the animal agriculture industry creates meat (such as supplementing and fortifying the meat) it is extremely easy to get away with not planning meals with an omnivorous diet.