[lathspell]

The magical powers that the elves posessed were not those that we simply imagine: fireballs here and there or a chain lightning across ten Orcs.
The greater power they had, I think, were in words and songs of power, and they were made for things dear to them. You mention the three elven-rings, they do give a lot of power to the one who posesses it, but it will only give power to the wielder for the thing that it was made for. in case of the elven-rings that was:
- protection
- healing
- preservation
As I noticed from Galadriel elves themselves do not understand the word 'magic' for they themselves use it daily and the word is also used for the tricks and deceits of Sauron.

Nevertheless I think the Elves didn't have much magical powers in the way of blasting and killing. There primary thoughts were to keep the world as it was when the Rings were made, not to fight with someone and win wars with great strength.
Maybe the greatest elves such as Galadriel and Glorfindel had such power in larger amounts, but I think they would still refuse to use it until there is no other way.

I don't think it would matter that much if they had used such powers in the Great Wars of Beleriand, for Morgoth had slaves as well with great magical powers (Balrogs, Sauron, etc.). Also, I believe, I read somewhere that the usuage of the 'evil ways' of magic are corruptive and should be used as less as possible.

Hoping the answer has helped in a way.

greetings,
lathspell