Those you have mentioned are the Major concerns for the majority. What concerned me most nowadays are the people behind who's trying to take crypocurrencies down. Government, Hackers, Banks, and Big Time Businessmen they are all against the success of Bitcoin in the market. Also these pump and dump situations, because I think only those who are already rich becomes richer while the others (including me) are working very hard to become rich, I mean they can easily manipulate the prices in the market by putting huge amount of money into a specific coin and suddenly pull it all out when it turns to be very profitable. Isnt very unfair for us, this is clearly taking advantage, our loss is their gain.