Second, elves were both taller and more slender than men, and used weapons of different design. Elven swords weren't like mannish swords. Giving out weapons and armor to men would have meant armor that didn't fit and weapons that they didn't know how to use effectively, creating large penalties than the +1 from the weapon.
It was a long weekend and i missed out a lot. Training on Friday and Sunday, 8 mile run on Saturday, followed by a Saturday night DnD session (anyone remember those, it's why we are here

); and only now on a lunch break do i get to write a bit. This is not meant as personal response to Maxperson, but i had to start from somewhere.
First of all, related to the quote above. Elves and Men, were much more interchangeable then Dwarves and Men. Taller and slender they were, and younger looking but still from a first glance you could not distinguish between them (especially the men of the West). Turgon even left a full set of equipment for Tuor (hauberk, shield and sword.... possibly a helmet, i don't remember) and it was never implied it was any different then what the rest of his household had. Turin was equipped as a knight from Thingol's guard as well. Gandalf is clearly human, and he wields Glamdring. I don't think there is any reason to believe elves use incompatible equipment to humans.
Now, on the nature of Thingol's dwarven armory. There is just no way of saying if it was magical or not. All we know is that dwarves made stuff of higher quality then most elves (definitely better then Thingol's Sindar). But were they magical? Nothing indicates so. Even Narsil had no apparent magical properties before being reforged. But's lest step aside from that, just one moment. By the time of the Counsel of Elrond, by Gloin's and Gimli's words we are informed that dwarves too lost lots of their craft, despite making some progress in establishing new foothold in the Lonely Mountain. And justly so, as some of their finest smiths were from Nordod and Belegost, both lost at the end of the 1st age. IRC only in mail making have the dwarves of the 3rd age regained some former mastery and possibly even surpassed their forefathers. Aside from that..... again, no indication of any magical properties of the equipment of either Gimli or Leglas. It is even stated that "dwarves make light of burdens" when Gimli takes his armor with him, which at least to me sounds like dwarven armor (mail) isn't any lighter then usual.
On Dwaves being stubborn and stingy. Indeed they were.... but not when fighting a common cause. The folk from the Blue Mountains equipped Thingol (though probably for a price) and Thorin did Bilbo a shirt of mithril for crying out loud!
As to the balrogs and their physical form being vulnerable to common damage..... this might as well be so..... but not because Saruman was killed by a knife or an arrow. Saruman was in mortal form, fallen and mortal when struck down. However, at least in the early writings, balrogs were slain but falling od a cliff, drowning and fighting powerful Eldar and one human, Tuor. We could argue that Tuor and the Eldar were well equipped, but that does not account for the other cases. And yeah, that was way back, when balrogs were supposed to be more numerous, but less powerful. But again, is a far stretch to believe that normal damage could kill one? Consider magic in Tolkien's world. Aside from divine magic, most of it is actually elemental and/or manipulation of matter. So, if a wizard could slay a balrog with say, a lightning, or making a large rock falling over it, why a large enough damage from a "conventional" weapon do it? In this case, it is only the skill and "durability" of the fighter that matters, not the weapon.
And finally, on the trip to Mordor....... Have we forgotten, what was said in the counsel? Sending Glorfindel with them was suggested. Sending a company of Rivendell knights in full mail was considered. In the end, a conclusion was reached. Sauron is too clever to be fulled or tricked. He we would expect every "wise" move they could make against him. So what was the least he would expect? Something that in his arrogance he might overlook? A small set of feet, secretly and beyond all hope sneaking in and destroying the only weapon that could overthrow him. They knew they won't win by might, wisdom or magic. They hoped they won't lose by foolishness. A "fool's hope" they called it. And it relied on friendship and loyalty. And that is what the book is trying to convey.