Sasuke has all my respect for the sh*t that he has done mate, really! OFC like every other character, he has had his luck once or twice... after all, if it weren't for chiyo gaara would have been already a long gonner for instance. Nevertheless, i cant say that amaterasu is the most powerful technique, and sasuke is the master of it...
The strategies that u mention; ofc they are good strategies - i definitely believe that sasuke has a vast arsenal of things to use. But i cant say that its the best technique, i can't say that sasuke can beat naruto with that technique because he has to find a way how to hit naruto first with those techniques in a limited amount of time. Naruto can go on for ages against sasuke cuz of his chakra... We have seen so much development from naruto lately and this i believe is what has caused him to go further compared to sasuke. Sasuke's turn is going to come soon again
EDIT: i just got reminded - amaterasu has failed to burn something, and that is gaara's infused sand