quoted for truth.

there's no easy way to predict how much you'll save if you get an inverter aircond. too much variable is involved.
but if you have a small room, little to no cold air escape to outside, by all means get an inverter.

TNB rates would just increase and increase and increase because we need to feed the IPP crony. and now since even royalties wants a piece of the IPP pie, there's no foreseeable stoppage to the increase.

larger rooms would also benefit from inverter, but it'll take more time for the compressor to operate under reduced load. inverter AC would have no time to run under reduced load if you put it at the living room with massive opening everywhere or if the doors are kept opened frequently.
in that case non-inverter AC would save you more because it's cheaper to buy, cheaper to maintain, higher BTU compared to inverter and doesn't have the losses associated with DC inversion circuitry.

it doesn't work that way. if you have a large room, you can't use a low watt AC and expect it to cool down the room easy. one more thing with downsizing the AC is that the compressor will be operated continuously, without any pauses in between, which will lead to premature failure.

it's a known fact that an AC motor needs to cool down in between heavy load. a downsized AC will have no chance to cool down which will affect the longevity.

not necessarily. york 1hp is 10,000 btu/hr. 9,000 btu/hr is the usual but some might be more, or less.
1hp is usually 746watt, but it's not an absolute rule. some might be more or less depending on the model.

yes. but if 1hp is installed to a hall sized room, then no matter how many fans it won't be enough.

it's advisable to run the aircond with a fan to improve the circulation and get the additional wind-chill effect, but downsizing is still not recommended.