In fact, even though Thrall killed Garrosh with

To be honest I believed it was due to garrosh's exposures to the evil gods of the sha during the Pandaria's mists which drove garrosh WOW Burning Crusade Classic Gold completely insane and gave him that hulking dire troll like physique. Before that even in the Icecrown raid you can see that garrosh was much smaller and thrall was larger than him. Additionally, he joined with the iron hoard and grew stronger in the hands of those orcs.

He put in the work and grew stronger because of his "real gangsta gangsta iron bros".

I think that thrall was in hiding from the fight due to the belief that he was the one to blame. He still felt that way until when he talks to his mother in Korthia.

Garrosh knew he needed to be killed however it was only a last resort. Yes he could've gone the way of the warrior and cut of his head or cleaved him with an axe or even brutally strike him or smash his head by using the doom-hammer, however perhaps that would have been too brutal. He chose to use the electric chair option that allowed him to be killed with just one bolt of lightning. I'm assuming that the death was relatively painless to garrosh. At some point, the lightning strikes and he loses his senses. He is dead instantly after the shock.

I'm trying my best to convince you that the thrall of the warrior was not able to be killed. Garrosh would've suffered a more painful and brutal death. The warrior is honored. The wild one is the shaman. The elements are wilder and uncontrolled. They push and stroke you and you'll be destroyed with their power in a matter of minutes.

Additionally, it could be that thrall has lost his warrior-like skills because he hasn't practiced enough. He is mainly using his shaman capabilities at the time of the war using archimonde. Perhaps thrall is less skilled in the field of battle since when he was a warrior. With the dragora in his hands, he is more warrior like and could probably kill makgora day garrosh using an axe "for Azeroth!" Like it was the case with Helya!

In fact, even though Thrall killed Garrosh with his shamanistic powers he was still feeling guilty about how he dealt with it and how Garrosh ended up being the result of Thrall's decisions and all that led to him losing his power.

Did he truly lose his powers? He still summons earth bridges both in legion and within the sanctum of domination. It's probably more about him refusing to use the powers he used to take out garrosh.

He feels guilty however he's not embarrassed. When he talks to drake, He mentions this to her in korthia. She assures cheap WOW TBC Gold him once again that it isn't his blame.