If someone asks me if the existence of bitcoins is a threat to jobs and national currencies, I will directly say 'no' to the answer. People know Bitcoin is an online platform where a job holder, a retailer, a trader or anyone; holding any business, can do with Bitcoin. None will have to quit his/her jobs to go on with bitcoins.
For a wise and cunning trader or job holder, bitcoin must be an extension and nothing else while it has no connection with leaving jobs or business. Therefore, the existence of bitcoins is not a threat to jobs and national currencies rather the extinction of bitcoins might be a threat.