What is the "recommended" gear to enter each Turn of Binding Coil of Bahamut?

[TimeZero]

Get your Relic to +1 which costs 900 Myths as it gives the largest initial boost.

And doing all that AK running will net you 100 Phil tomes a go, so you'll have plenty to upgrade yourself with some Darklight pieces too.

You'll want to buy the Darklight Ring & Bracelet first, as the DL ring is unique and you cannot have two, which is why Strategos Ring is your ideal 2nd ring. This means you should have Strategos Earings, Necklace & Ring from AK with Darklight Bracelet and Ring filling out the remanining jewelery gear slots.

That is what I've done since it seems only logical to me to upgrade the worst items I had at the time: Earings/Bracelet

I currently have: DL Earings, DL Bracelets, Strategos Necklace-Ring-Boots, Warlock Hat-Pants

I was planning to get AF2 Chest with the Myth tomes instead of the Relic+1 since it would upgrade from ilvl 55 to ilvl 90. After the chest I would go for AF2 Circlet, meanwhile going for DL Ring and Belt.

[Thorauku]

I was planning to get AF2 Chest with the Myth tomes instead of the Relic+1 since it would upgrade from ilvl 55 to ilvl 90. After the chest I would go for AF2 Circlet, meanwhile going for DL Ring and Belt.

Don't. Just don't.