Cardio burns calories. Cardio can help ensure that you are in a deficit, but if you are eating more than you are burning (burning as a whole, not just within that workout) then you will not lose fat. Furthermore, too much cardio can cause muscle loss.
This is true. Typically people with less body fat are less buoyant in water than those with more body fat. This also means they are more susceptible to cold temperatures than their chubbier companions in survival scenarios.
this collection is like 30% bullsh#t. Same with #1: nobody is talking about the individual cells, it is not meant literally.