That depends.... ....On the herb. If you eat a salad containing things like lettuce and celery, you are eating uncooked herbs. Clearly, that's not only safe, but healthy. There are, however, many herbaceous plants that are not only not safe, but could be potentially fatal if you eat them. Common examples are rhubarb leaves, bleeding hearts, lily of the valley, and larkspur. If you're not sure, don't eat it.
Maybe but it depends. Eating uncooked herbs depends upon which herbs you want to eat. Some plants are not safe for human consumption no matter whether cooked or not. Others are only safe after being prepared. With some, you can only consume certain parts of the plant but not other parts. So unfortunately, there isn't a general generic answer to your question. It can only be answered with regard to a specific herb.