I'm curious what treatment of Pelinal is like in the 2nd Era, specifically during the time-period immediately preceding ESO. How many worship him? Have all the legends been properly crafted? Is the Song of Pelinal yet in existence? I've been considering playing a character stirred to hatred of the Dominion and using the legends of Pelinal as inspiration and want to know if it makes sense.

The Song of Pelinal appears to exist by that time.

Hans The Fox: AKA Harrald Harry-Breeks: AKA Pelinal Whitestrake was dead by the 2nd era as you already know.

As for Pelinal being worshipped? I don't think he was ever really worshipped.

the closest to worship you would find for Pelinal would be http://www.uesp.net/wiki/Lore:Knights_of_the_Ninewhich wasn't founded until the 3rd Era 111 and had its headquarters in the Chapel they built in the West Weald in Cyrodiil.

However, the Order was soon splintered by pride and the others wearing the Relics into battle. The final staw that broke The Order of The Knights of The Nine was the http://www.uesp.net/wiki/Lore:War_of_the_Red_Diamond#The_War_of_the_Red_Diamonda civil war over whom would get the Imperiel Throne after the Death of Anitochus in the 3rd Era 120. It was largely started by Potema, The Wolf Queen of Solitude, and her son Uriel III.

You could roleplay your own character that is searching for the Crusader's Relics. As the Knights of the Nine were not the 1st to search for them, they were only the 1st to be successful in finding some of them.

I think there is plenty of room to roleplay that scenario, You should have no problem letting your mind run wild and go with it where you want!

I hope I was of some help to you.

The prophet in Anvil seems to imply that there was a time when the Imperials at least honored Pelinal: notice that he calls him Saint Pelinal, suggesting that he was at one point canonized in the Church of the Nine Divines (a kind of Archangel Michael-situation, where he is simultaneously a god and a saint, I guess). Of course, we've been told of various "hero-cults" in Nibenay dedicated to the memory of Reman, Morihaus, Emperor Zero, ... It would be strange if Pelinal wasn't worshiped somewhere among them. There's no telling how popular his cult would be, though.

I think you would find it interesting that the chapel of the eight is there in ESO with it's own knights.