Is auricularia auricula-judae completaly safe for human? can it be used 2g per day for many years( through supllements) without any damage on health?

Probably not: When not talking about real, purified, studied, approved medications, the answer is usually, "Nobody knows for sure." That is due to the lack of good research studies and the lack of uniformity in the product, which means one bag of product is different from another bag of product, which is usually different from the bag of product that got studied, if any were studied. Buyer beware; user beware.