"Natural Flavours" - I usually consider that these flavours were once part of the thing they taste like and derived from it. So natural vanilla came from a vanilla bean. Artificial flavours were created by combining chemicals to form the main taste ingredient of the fruit or whatever.

As for the carbs, if they are listed like this:

Carbohydrates 10 grams
.............Sugars 5 grams
.............Fiber 3 grams
.....Other Carbs 2 grams then the Other Carbs are part of the total of 10 grams.

But if the indentations are like this:
Carbohydrates 10 grams
.............Sugars 5 grams
.............Fiber 3 grams
Other Carbs 2 grams then the Others are NOT part of the total carbs & you'd have to add them to the carb count.

Personally, I have never seen this on a label, so maybe the manufacturers are getting honest.

Or maybe the Others are things like glycerine or sugar alcohols that are considered as 'not affecting blood sugar levels. Be VERY CAREFUL of these last ones - not everyone can eat them without reacting by producing insulin.