Other than the Silmarillion stating that they equipped elven armies with weapons to fight Morgoths armies, which included balrogs and other fallen Maia. Hard to equip entire armies to fight things like that if they aren't magical and in large numbers.
Specifically, they equipped Thingol's armory with weapons (and i don't recall if it was armor as well), but it is never stated they are magical. Thingol's army never really accounts for any Balrog kills (which doesn't mean there weren't any), however do notice that when Beleg has the freedom to chose a weapon, any weapon, from the entire Thingol treasure he picks a sword forged by a dark elf named Eol. And that sword was probably at the time one of the deadliest weapons in Middle Earth (and had a will of its own). If some of the wrightings are to be correct, it is that sword that will strike the final mortal blow to the returning Morrgoth. Even that sword (obviously "magical" even by Tolkien standards) did not kill any balrogs though..... it claimed a dragon, but that is a different story. The only cases of Balrogs being felled in battle that i can remember were actually in fighting with the Noldorin princes, probably most of them during the siege of Gondolin. I would have thus attributed the kills to the divine nature of the Aman originated high elves themselves and not their weapons, but then if i recall correctly, Tuor actually killed some himself. Still.... even in these instances (of arguably lesser Balrogs as presented in Silmarillion then in LOTR) it is always the nobles or their most faithful allies/guards that do the deed. And those allies would be equipped with weapons made in the undying lands and/or specifically for fighting the servants of Morgoth. In any case, there would not be many of them. Even so, most of those were still lost during the Fall of the Noldorin princes and following War of Wrath.
There is however another way of looking at the weapons aside from the magical (spirit imbued) weapons of the elves and the masterwork superb weapons of the dwarfs. Maybe like all tech, weapons were made with certain use in mind. Maybe Noldor weapons were made to fight the servants of Morgoth and were best suited for that. On the other hands dwarven weapons were maybe made to be supremely sharp and of high durability, thus being able to cut better through otherwise difficult to cut/pierce objects, like dragon scales.
EDIT:
Sorry for taking so much time and space (this is one of my favorite topics after all), but i nearly forgot why we came here:
Here is a list of spells in 5E that could qualify for part of Gandalf's repertoire:
4th level:
Control Water, Otiluke’s Resilient Sphere (arguably, could be globe of invulnerability) ,
5th level:
Wall of Force (alternatives bellow), Scrying (arguable),
6th level:
Chain Lightning (In Goblin town, could be regular lightingbolt), Globe of Invulnerability (alternative to ORS), Guards and Wards (alternative to wall of force), Sunbeam , True Seeing (only on himself)
7th level:
Symbol (more exotic version of warding)
8th level:
Sunburst
Unfortunately, no spell i could find is equivalent to a fireball centered on the caster. Some of these could be innate abilities of the race, but either way, his effective MU level would be at least 7 or 9, and could go all the way up to 15.
I've read the Unfinished Tales. It's one of my favorite collections of Tolkien's work. I don't recall specifically, however, the mention of Gandalf's vassalage to Manwe or Varda. Is it mentioned there?
Good question. I have read it only once and i can't recall it all that well. And i am too tired from scrolling the Silmarillion to look for the answer right now. I hope someone can make it more clear.