1. They are neutral.
2.Yes, i do not comment muchon social networks, and when i comment i try to express myself as in real life.
3. Yes, just comment criticizing in a way that does not leave the other hurt, without doing offenses.
4. It depends, if it is to disrespect the other person is very bad, but you can express your opnion.
5. Usually i'll praise that person back or i will noot answer anything.