I havent got any problems, actually i like the site pretty much. Still never keep extra coins in exchanges, even big and trusted. Bigger they are, harder they fall.

Only mintpal related problem i have heard for a while was caused by hacked bitstamp ticker extension in google chrome which changed the mintpal deposit addresses, but it was because the extension not because the site

Edit: and ofc they are willing to add pos hypecoin, every exchange creates profit, and well obviously they want to maximise it