This isn't about Scar directly, but this is about Mufasa's character. Which you suggest is hypocritical; cold to his brother; and not to mention arrogant.
[quote="Regulus"]

Oh, I'm sorry, I can't hear you from all the way up here.[/quote]Observing his kingdom like any other King would is somehow him saying that? Far from it really.
[quote="Regulus"]

How dare you not bow down to me like everyone else![/quote]More like how dare you disrespect me, my son, and the whole kingdom for your own selfish motives.
[quote="Regulus"]

Jeez, that guy is such a pain in the butt to deal with because he doesn't fear me.[/quote]I think you completely misunderstand the entire significance of that scene. He is in no doubt frustrated with how his brother treats everyone.
[quote="Regulus"]

Look, Simba. Look how much better we are than everyone else.[/quote]
That is so far from what really happened. Honestly I think you're a Scar fan.

He's only showing the Kingdom to his son. Explaining to his son the boundaries of the Kingdom. Never once does he mention being better than anyone else.
[quote="Regulus"]

As king, we must respect all living creatures...

Except these guys. They can starve to death for all I care.[/quote]Clearly that is not the case. If it were than why is it that even out of Banzai's mouth did he say to Shenzi, " I thought things were bad under Mufasa?" Clearly they didn't like being in the outlands, but they had some source of food under Mufasa. There was something for them unlike under Scar.
[quote="Regulus"]

You see that bird over there? That's my majordomo. Go ahead and pounce on him. I like to watch him get hurt.[/quote]

It was a pouncing lesson and he even warned Zazu in the original film.
[quote="Regulus"]

That's right, run away from me because I'm the great and powerful king. And if you ever come back, I'll kill you![/quote] Oh I don't know maybe they tried to kill both his son, and son's betrothed wife Nala.
[quote="Regulus"]Even if Scar is the whiny baby you claim him to be, the way to measure a society is by how it treats its weakest members. A king, above all, should realize that. If he truly was the great king that he was intended by the writers to be, then he would not have to resort to his brute strength in every situation to get his way.[/quote]If that doesn't sound like something Scar would say I don't know what is.

Define a time when he used "brute strength" to get his way. Not once. The entire movie he only attacked Shenzi, Banzai, and Ed after they tried to kill his son, and Nala.
The bottom line is that no Mufasa was not perfect, but he was indeed a great king. Simba did have a right to replace his father in the end. Simba took the kingdom from ruins and brought it back to thriving as it once was. That alone is an accomplishment.