League of Legends (LoL) Item: Relic Shield

This item is much better considered in higher ELO play, in lower matches, people frequently and surely will berate at you for killing the minions, that's why you MUST let your carry partner know you're using it, because can turn all the tide of the player interaction in a match.

To make it easy to understand, if your Relic Shield Supp makes the killing blows, then:
1) it will heal the carry and himself for a little scaling amount
2) it will yield half the gold for both of them
3) that creeper kill will count for both of them, not just the Shield bearer.
4) if the shield carrier gets 500g it will upgrade into a much better shield, the sooner the better, so you, as a bottom lane carry should actually consider this.

And is this last point where I don't see this item anywhere avoiding selling and I might be wrong. Making the 500 gold sharing the profits with your carry can be a very daunting task, I have only completed that quest after minute 20 and very few times so far.

Otherwise is a great starting item and I see that some ADC's are picking it along with Kleptomancy to get an eyebrow raising gold farm spike.

I don't get it, you should leave the farm to your ADC so why should a support like Thresh use this item? Isn't it better to use Talisman of Ascension instead to get gold and mana regen? Just asking, i'm still kinda new to the game :)

Hm does this work with Feast , i mean... does the "Clarity: Allies who benefit from Spoils of War now also gain +1 to their minions killed score" effect, activate it?

The recharge is a bit long... tho I do like the nerf of melee-only execute

Yes.
That's why it was OP until it got nerfed... (a little, double Targon might still be viable)

This might sound very noobish, but does the passive give you gold for executing the minion, AND gives the ally the bounty?