As an ex-UN functionary (with nice light-blue passport and white Landcruiser) and having seen how the organisation works at the 'sharp end' (well... semi-blunt end), I suggest the following:
Create a three-tier system within the UN.
Tier 1: 'UNSC' but with only democratic countries that have nuclear weapons (US, UK, France, Israel, India) and Japan and Canada (because they're decent). Russia and China can have observer status but no voting rights.
Tier 2: Democratic countries that follow the rule of law, etc. (i.e. civilised countries e.g. Germany, Sweden, etc.)
Tier 3: Non-democratic countries/dictatorships/absolute monarchies/scum and other socialists.
Only Tier 1 and Tier 2 can vote. Only language permitted is English (to keep costs down and to be a marker of national advancement). Tier 3 have observer status only.
Tier 1 and 2 countries get to use the international financial markets at 'AAA' rating/pricing for borrowing money. All others have to pay BB- rates of interest to give them an incentive to sort out their shit. Also all Tier 1 and 2 countries should have preferential trade tariffs and Tier 3 goods are taxed at a minimum of 20%.
'Westernise' the UN bureaucracy: get rid of all the 'affirmative action' targets that have resulted in corrupt little shits from Zimbabwe and other shitholes getting important jobs and instead give the jobs to Tier 1 and Tier 2 nationals who have the relevant experience and qualifications. Tier 3 nationals would be forbidden from holding any UN job or receiving any UN funding.
As to the OP whining about the evils of capitalism: it is capitalism that has seen the greatest ever reduction in global poverty and it has been socialism that has seen the greatest environmental damage ever done to the Earth (and I've been to many of these places). It isn't coincidence that China, under communism the most polluting and polluted country in the world, now that is has capitalism under a one-party rule, is the world's largest maker and user of solar energy.