Not a chance in hell......madra is simply too powerful for sasuke. Last time I saw the series madra was toying with the five kage while sasuke was barely able to survive against one when he came to the land of iron.
Well he is one of the fastest ninja's till date even without his flying thunder god jutsu. His knowledge and mastery of jutsus was second to none and he was one of the most tactical minds around. Brains and brawn.....you just cannot beat that combination!!
Oh hell no. Neji was far too experienced with the byakugan and his kaiten could easily block most of lee's attacks. Neji was far too powerful for lee at that time.
Jiraya and Itachi. I know that their deaths were absolutely necessary to move the plot lines forward......but damn those deaths broke my heart so......you're basically saying that the second most important character in the anime should die??
To give you a short answer : "Cannot be determined." The only person who can say what will happen is kishi himself and until he says something on this topic everything is just speculation.
I like his resolve and freaky nature. As for Tsunade I'm with you how could she become hokage if she can't stand blood? But In the episode arc where naruto and jiraiya are looking for her jiraiya mentions that the third wanted her to be the next hokage so...... I guess their was no other option. Actually, if I remember correctly, the third wanted oro to be his successor but......well you know the rest of the story!! Jiraya was next in line but he refused and Tsunade was the only one left.
In response to your last point tsunade could not defeat orochimaru......she struggled in her fight against kabuto and barely managed to hold her ground against oro, even when jiraya had, to some extent, recovered.
PS: I am terribly sorry for double posting!!!!
As far as I can remember (I may be wrong) they were called the legendary sanin for their exceptional teamwork.....the title wasn't given to them because of their individual abilities......so in that regard : NO
Personally I like him most of the three sanin........he might be a big pervert and everything but underneath all that you can't deny that he is an excellent shinobi.