I think the only real challenge would be if China were to continue its growth for the next decades or so.
1 and 2 are not really an issues imo.
  1. Doesn't matter because there is only one real competitor for SWIFT, and it's the CIPS from China, which is extremely shit and good luck convincing nations move from the west's approved payment system to china's approved payment system. Global trade is about making nations work together to build, and using it to deter bad behaviour. Even Swiss froze Russia asset, which is just as big if not more.
  2. Mistrust between US and EU aren't rare, but this wouldn't be an issue because mistrust and corruption between BRICS nations are definitely even larger.
This is also why anti-west also go for the "XYZ is just a lapdog for the US", they want to use the public to break the alliance, not understanding countries reaches decisions after discussion as an alliance.