Important actions are those that are realistic and have an impact. For example, cancelling coal/gas power plants, building more CO2-free power plants, getting rid of combustion motors in naval transport, etc. Everybody can have an AC if we have CO2-free electric energy production.
2) Yes, developing-economy per capita energy usage is going to go up while they catch up to developed-economy standards of living; that's happening in all categories. Developed economies still need to reduce their energy usage. e.g. we're not stopping our switch to electric cars just because half of India is getting their first gas-powered scooter.
Everyone can have A/C, but we need to keep our usage as low as is feasible.
We need to fix overall energy policy, make everyone pay for their consumption just amount, and keep fixing the damn production to get carbon neutral.
There are many ways to mitigate climate change but I don't think that telling people what should they do with electricity is the way to go. Perhaps focus more on how the energy gets produced, not how it is consumed.
If the advice is sound, maybe we should be telling people about it. For example, we could recommend to replace cheap ineffective ACs with effective but expensive heat pumps and some small percentage of people will do that. But this won't do much to mitigate CO2 production. AC energy consumption isn't a major driver of CO2 pollution, fossil-fueled transport and coal/gas power plants are.