Dragon Tears are Qualis Gems, you can get them by capturing the named leaders of random armies like Wolfbode the Slayer or Maltise. The other (easier) way to get one is to do the Noldor tournaments held from the 1st to the 4th of every month. The vendor in the noldor city generally gives better troops.

One you can find in Rane (Ravenstern). When you enter town turn left and go to dead end in heap of hay you'll find chest, in it will be 1 Qualis Gem.

OR if you're lazy or doing a youtube series and need them for behind the scenes, you COULD use the cheatmenu, the game doesn't and cannot punish this, as it is a bug in the game, but you still pay for every item you take from it, and this can be fixed with cntrl + x in the inventory screen or in the cheatmenu itself, this gives you 1000 denars a press.

Then there is the "Other way"... you need a Qualis gem and it involves gambling.. one of the many many Easter Eggs in the game.. in this case it may give you a small company of Noldor to follow you.

So I did not take the passive route towards the noldor and when I finally beat an army AND got a dude as prisoner he showed my the secrets of Noldor weapons and I let him go. How do I use these secrets to make the weapons and armour and such?

He unlocked items for your custom knighthood order. You can't forge them for yourself.

Will it be possible to play as a noldor?