Main customs and etiquette...
haha, yes the sheep head story is true! Although I haven't had the honour to attend an event like that myself.
On an event like that the most honoured guest is also asked to speak and toast to all.
When entering a house you (offer to) take of your shoes.
Languages are mainly Russian and Kazakh. English is less spoken, but this also can depend on which part of the country you are in.
Kazakh government is actively promoting Kazakhstan as a trilingual country (Russian, Kazakh and English), but English is not widely spoken.