assalamu alaykum wa rahmatullaahi wa barakatuh
Jazaki Allaahu Khayr sister Asja, that quote reminds us of the disbelief of the Raafidah. - An individiual Raafidi, we can not judge, but, if that raafidi has the same beliefs as the sect they belong, then they are not believers. i.e. they say and do the disbelief of Raafidah.(which you placed kindly in your post)
Its interesting, its kinda linked to this, the Jews, (the cousins of the Raafidah) hated him much, and made many fabricated stories about him, just as the dispicable Raafidah do the same with the greatest Muslims of all, the companions of the Prophet Muhammad
I never heard or saw Michael Jackson do Shirk, nor kufr.. Nor did he curse any of the Sahaba, nor did he go into exaggeration of any of the Muslims, Michael Jackson said the Shahada.
So, yeah, the Raafidah are worse enemy to the Muslims even than the disbelievers. If I had to choose between sitting with a Christian Priest or a Raafidah Imaam who says A'isha the mother of the believers is a whore, and who cursed Abu Bakr, Umar, Uthmaan and many of the other Sahaba, i would choose the Christian.
Shirk, associating partners with Allaah, and the kufr, sayings and actions of disbelief, are what make people disbelievers. Even if they verbally say the Shahada, -- it means nothing, if their beliefs break it.
Even If someone does things, like live a celebrity, somewhat eccentric lifestyle, but they do not do shirk and kufr, then we can not call them disbelievers and if they are Muslims, we should have the shame and humbleness not to speak bad and judge them.
Assalamu alaykum wa rahmatullaahi wa barakatuh