Sasuke's main battery has usually been charged by hatred. The more hatred he gets, the stronger he becomes. Now you are correct that the Uchiha name drove him on, but it was also his hatred of Itachi and his dreadful goal of getting stronger (in order to kill him) that lead him to his actual strength. Once the Uchiha massacre occurred, Sasuke truly embraced his hatred.
Sasuke definitely took sacrifices for his power too; I think that is generally overlooked by some. Would you rather train 3 years with Jiraiya or under 3 years with Orochimaru (who wants to take his body)? He constantly worked in the dark to receive the power he so desired.
Sasuke sacrificed the village's comforts in order to get this power. Hard work over gifted talents is a key part in this manga, but pain, especially the emotional kind, is one of the most dominant sources of power in the manga. IIRC, pain is what got Naruto to learn Sage Mode in the first place. Naruto's encounter with Sasuke under the bridge explained this a bit. If the Kyuubi out-right said that he was comparable to Uchiha Madara, that must say something about his future! Naruto isn't a shrub either btw >_<
No what I think is bothering you is the speed by which characters learn/master these jutsu. If it helps you at all, remember that Sasuke was commenting on how much pain Susano'o caused at first. That's Kishi's way of hinting towards experience over time me thinks.