Next to Bitcoins there are several different other crypto currencies like DASH, ETC, ETHEREUM, LTC, XRP. Do you believe in them? Are there any Advantages and/or disadvantages?

Its fine in my opinion , because it has own advantages such a trading , you can trade alts for btc which is quite profitable right now , the disadvantages is most of them probably shitcoins and it will ended up as a scam and it will cause bad problem for traders ,better use othet alts if necessary