I don't know how to multi-quote :|
1. - My flavors can vary from 0,9g to 1,04g... meh, 1g is accurate enough for me.
2 & 3. - If, for some reason, they change their mass/density/whateversinceI'mnochemist it will be reflected whether you use ml or grams. 1 ml of VG without moisture will not...