It's riffs, and there melodic death\power metal not heavy metal, and although Alexi is very skill-full on a guitar they are known for there great guitarists and godly keyboardist, drums aren't nothing to special. Not that Jaska isn't talented it's just that he isn't above average with the better half of the metal world. as for singing, Alexi just yells, he said it himself in many interviews, it's not "good" but it's necessary for the band to be what they are and it seems to work well. So if you consider there vocals something that makes them such a great band you obviously have no type of any form of musical talent. (although beings the band has already been so distinguished as they are it would probably be for the worse if they changed vocalists now.
as for the songs you picked they aren't that notable, and isn't a whole lot of talent inside, and anyone can cover a band so there is no point in covering a song and saying it's one of there best...
These are some of the more notable songs by the band, for skill and performance.
bed of razors
follow the reaper
every time I die
in your face
knuckle duster
mask of sanity
tie my rope
towards dead end
six pounder
are you dead yet? (debated if I wanted to put this one in or not.)
