The issues you mention are mostly the trading platform dependent. When you are choosing a reputed trading platform, you will not face any issues.
Not in bitcoin trading, but in my Forex trading I have faced the many issues like order is not getting executed and not connecting to live market are some of major issues, I have faced in my trading.
This is correct, those issues would be on the platform and as a trader we should really find a reputable trading site if we dont like to experience this things well there are really times that we cant avoid this circumstances but we could always contact their support if we experiencing problems.
I haven't any issues either as I trade even though I am still new with trading I am able to be comfortable. But if I have issues I think there is really none and that is just going to depend on the trading platform that you are using. And on bitcoin, there is no issue at all as the bitcoin trading is already well established.