We have used this mobile quite extensively but did not encountered any heating issues despite playing games or videos for longer hours.
Basis on my extensive use of Honor 8 for about 4 months, I can say that these are the biggest advantages of Honor 8.
01) Super Aesthetics
02) Superb Camera Quality
03) Good Internal Software
No. You cannot record 4k videos but you can play 4k videos on Honor 8.
Honor 8 has mono speaker.