I work in energy efficiency, so bitcoin makes me cry. Any sane clean energy transition plan requires significant savings (no you can't just build a bunch of PV). But while we are killing ourselves trying to get people to adopt green buildings and low energy appliances, along comes Bitcoin where people just burn energy for nothing.
It doesn't sound like you really understand how Bitcoin works. If Bitcoin were to become widely adopted and supplant traditional financial institutions, the environmental impact would be enormously net positive. Sure, it takes energy to confirm transactions. But, we could massively decrease energy consumption by eliminating the need for: bank buildings, armored vehicles, physically printing money, etc.
Bitcoin as of right now uses over 5000x the energy of a credit card transaction. That's a flat-out waste that none of your suggestions could ameliorate - at a rate of ~325,000 homes worth of power per year and rising. It really sounds like you don't understand how Bitcoin works, nor how blatantly wasteful it is.