San-J Tamari Soy Sauce is. Most soy sauce is not, its ingredients are Water, Wheat, Soybeans, Salt. Wheat is used to ferment soy sauce rapidly.
No, this is called Cross Contamination. You have now put wheat gluten on a gluten-free pizza.
The Gluten-Free diet is not a weight loss diet. Most fried foods are breaded which will help you cut those out of your diet. You still need to make healthy food choices, practice portion control, and exercise if you want to go on a weight loss diet.
A simple blood test can diagnose the probability of celiac. An endoscopy will be performed if the blood test is positive to do a biopsy. The villi in your small intestine will most likely be damaged if you have celiac disease.
Yes. It is also possible to have celiac without any other family members being diagnosed, testing has not been done until recently.
Read the ingredients label and check the manufacturers website. Naturally gluten-free products are a great place to start. Some ingredients are not as straightforward such as modified food starch, you must make sure it is derrived from corn not wheat. Malt is made from barley. Some manufacturers are better than others about listing wheat as an allergy, but most do not list "contains gluten". The United States has no labeling laws regarding gluten. Manufacturers also occasionally reformulate their products, occasionally re-checking labels of products you always buy is a good idea.
No, no, no, and no...
I'll try my best to answer your question about Gluten-Free and Celiac but I am not a doctor.