No its not. Its an ability of the Sharingan, the sharingan is able to predict movements, copy jutsus, and its capable of doing its own jutsus with mangekyou, those are the abilities of the "Sharingan". Its not a seperate Kekkei Genkai
Its an ability like how Byakugen is able to see chakra points, see 360 degrees, etc.
Its still part of Sharingans list of abilities, and thats why Sharingan is the best kekkei genkai, because it has alot more depth and abilities then most kekkei genkais.
Sharingan's abilities is to see what type of jutsu they are using, to pedict moves, etc. MS is a completly different eye technique, not every Uchiha knows MS, while almost all know sharingan.
Mangekyou is part of its abilities as well, there are different levels of sharingan, theres the one pupil, two pupil, three pupil, mangekyou, but its all part of the SHARINGAN Kekkei Genkei.
Its a matter of how much of the sharingan the user has mastered, Itachi for example has mastered the sharingan and thats why he can use everything, but Sasuke in the Zabuza saga when he first gained the sharingan (with one pupil, and then two pupil) was only able to predict.
a mastered Sharingan is the most powerful of the kekkei genkai on your list.
The 3 pupils are part of the sharingan technique which every Uchiha has. MS is a completly different technique that Madara, his brother, Itachi, Sasuke, and Kakashi have. MS is a jutsu of sharingan, but it isn't an ability All sharingan does is see what jutsu you are doing, copy physical movement, etc. Now you are going to add in EMS to sharingan to make sharingan the ultimate weapon, but it is a different eye condition that only 1 knows, and that is Madara.
Umm no.. not all uchiha's activate sharingan, not all sharingan users activate all 3 pupils, and very rare uchihas activate mangekyou (only sasuke,kakashi,itachi, and madara have)
Being a jutsu of the sharingan means thats its an ability, you attain it once you reach that level of mastery/kill your closest friend, it is still an ability of the sharingan.
I've listed the abilities of sharingan, thats the fact. Mangekyou Sharingan is not a totally different Kekkei Genkei, its an ability of the Sharingan Kekkei Genkai.
Sharingan basically is the ultimate kekkei genkai, and is much superior then the rest.