Inconsistencies in the book

Some ideas taken from the book which I have never quite understood, just to name a few:-

- Why did the High Elves have so little concern for ME during the LOTR, when ME was most at peril probably in it's entire history? Why didn't they help out more?

- The 9 Nazgul when together at night were close to Gandalf the Grey's power in the first volume, yet if Sauron had the Ring reclaimed then their power would become much greater. If this is so, doesn't that mean Gandalf would not have a chance against the Witch-King alone, or even against the lesser Nazgul, if Sauron had the Ring again? Is the legendary Gandalf then of no match when compared in power to the likes of Isildur & Elendil, who were considered to be mighty, & capable of holding off the Nazgul easily even with their Ring enhanced power?

- What happened to the Nazgul during the battle against the Last Alliance? Why were they apparantly so useless in battle against the enemy?

- If Sauron increased the power of the Witch-King in the third volume, how was this possible without the Ring? Surely the Witch-King can't be as powerful as he was when Sauron had the Ring?

- What was so special about the Sword of Elendil besides it's huge inspiration to the wielder? Was it magical, & if so could it pierce the Witch-King?