FYI, I consulted some DMM players, there'll be a number of changes to the drop table but if you're leeching Och, it's roughly 50/50 for 1 page. Hosting your daily Och (only one per day unless you're really lucky, which I won't count on) should give around 2-3 pages even if you don't MVP. So add in roughly 1 page daily from raid shop, you need 4-5 more pages, so leech about 8-10 Och a day? (Please note that these are just ballpark estimates.) May or may not be doable depending on activity of friends and union.
Lol, yeah, you can't bypass the 50 magna/globe requirement, and don't forget the 3 books needed for that weapon
Standard/expert/ultimate all drop cores, both tiers. Rags also drop cores, only the higher tier if I'm not mistaken (at least I don't remember ever seeing lower tier core in my drops.)
Fangs do not drop from anywhere except SP quests and gemcha right now (and 2/month from shop.) This is why I've been grinding SP caves during half off - and it's not just to save on HE - every element is open during half off, so I can farm the element I'm short every day as opposed to needing to wait until the right day to do it (not sure why they can't just open all everyday like they did with the enhance mats, it's like they have to make the most boring part of the grind even worst.)
Btw, it's not a bad idea to do all 18 standard and expert raids every day (and ults, too if you can) since you can't just like find one day to farm like crazy and be done with it the way you can for story mats. The fodder and eido orbs are also a nice bonus.