Picture and audio is very good. only problem with compare to DVD player is that sound output is very low (that should be the case with most of media player). but as you are using Logitech Z5500, there should not be any issue. just you have to increase sound level little bit more.
It does not get hot. there should not be issue while using for a long time.
It does not have one push music option. You have to select option from menu (Video, Music , photo etc..), once you select music, all audio file from pen drive /HDD will display and start playing one by one.
I prefer to select browse option from File Manager that help me to play music by selecting folder