So firstly from a rules POV Roleplaying Immunity to the RP effect of Unfettered Anarchy is just cheating. Also the Cambion Lineage, doesn’t impact on any of those specific RP factors.
More generally, it strikes me as trying the Empire equivalent of ‘my character is from an area with lots of Dragons so I should gain a bonus to resisting fire.’ You are used to enduring one specific set of RP effects trivialising that and turning it into a carte-blanche resist curses strikes me as boring and tenuous at best. Also on an OOC framework one of those curses is half a players mana production, the other is 2 seasons of a mana site, and a coven slot. It’s something a player has invested in inflicting on your character. (Trivialising and ignoring these effects is something people will judge you for.)
But also I think you are looking at this the wrong way, you everyday life is made difficult due to the Plateau but both of those examples are ones that would make living in Spiral far Worse.
Dreamscape of the Endless Hunt stops you getting restful sleep, it takes away normal tools you have to deal with problems. Also Fear is a negative emotion, Dreamscape makes being alone a frightening experience, which the Black Plateau amplifies. That sounds horrific especially when combined with Urizen being lowly populated and culturally introverted, and that the Black Plateau makes feeling safe around people difficult.
An anointing does mechanically let you power through that horrific combination of RP effects (although I think you need to be medicating with Vinum to stop the dreams),but you would be doing that be constantly drawing on and embracing that roleplaying effect. At which point the question becomes roleplaying someone who is experiencing chosen anointing at it’s fullest for most of their life. That rp effect is the mental crutch that allows you to function (That’s if the Druj haven’t pushed the Black Plateau back into needing more than an anointing to cope, at which point constant terror if you are alone, and you can’t feel safe around people due to the Black Plateau.)
As for Unfettered Anarchy that sound completely horrific in Spiral, because the Black Plateau is going to shift the balance of which emotions are constantly turned up to 11.
It also probably destroys all those little Urizenii coping methods, because you react to trying calm down with an outburst of emotion which is probably going to be negative due to the Plateau. There was one time when literally the only counter to the Black Plateau’s curse, had this RP effect, which Unfettered Anarchy sticks into a lovely loop of:
Experience Negative Emotion, try to resist using Crystal Clarity of the Rational Soul, this fails due to triggering Unfettered Anarchy which causes a strong outburst of the original negative emotion.