Brent/SSJ is legit. He used to work for an eSports group named NRG, something Ice was a part of for a short time. NRG had a house in Vegas where SSJ lives. When SSJ comes to LA, he works out of Ice's apartment, resulting in him and his clients (Baked Alaska, Anything4Views, etc...) becoming intermittent characters on Ice's stream. SSJ is disliked by Ice's community, who perceive him as a killjoy and the facilitator of "sellout" sponsorships . The most relevant example would be Nikita, a fan favorite that was essentially exiled from the stream by SSJ for reasons we only learned of yesterday; allegedly doing coke w/ Warski in Ice's apartment.
Ice isn't exactly straight edge but I highly doubt he fucks with illicit drugs. A single experience with MDMA is the only thing I recall him mentioning outside of the myriad of ADHD meds he hated taking as a troubled youth.
He's also been swatted over 40 times, so anger at people doing coke in his bathroom is to be expected.