Sub Job For Blm?

BLM/RDM is arguably the "DD" BLM. (Melee reference: WAR/SAM)
With "Fast Cast" giving you enhanced casting speed and slightly lowered recast timers, you can fire spells off faster. Refresh and Convert will play a huge role in sending your damage "up, up and away!".

You'll have the resources to keep yourself alive (Gravity, Stoneskin, Blink, Aquaveil, Phalanx, Mana Wall + Convert), but lack many "PT friendly" spells.

BLM/SCH is the "utility" BLM. (Melee reference: WAR/NIN)
You'll be able to the same damage you would as /RDM, in shorter bursts, but to do it in a shorter amount of time you lose out on DoT (damage over time) due to lower MP recovery (shouldn't be that big an issue inside abyssea, though I still manage to burn my MP dry when I want).

You'll have the resources to keep yourself alive, but you'll have to be out of "Dark Arts" to do them (decently well at least). You'll have access to some "PT friendly" spells, like "ghetto Curaga II" (Accession + Cure3) or status ailment removal (-na's/Erase).

You'll do a lot of bouncing from one art to another if you're aiming to make full use of both sides of /SCH.

BLM/WHM is the "support" BLM. (Melee reference: WAR/PLD)
You'll have no "Fast Cast" or "Casting time-" from /WHM and you'll sell your DD capabilities short. You'll still be able to push out some punishing nukes, but your DoT will drop drastically compared to /RDM and /SCH's that are going all out.

Your role /WHM should include Hastes, status removal (-na/Erase), "backup" cures. You won't "need" to burn stratagems to use this SJ to it's fullest (mostly because they won't exist for you). You'll have some decent self-defense (akin to /SCH) and you'll have a more "PT friendly" role.

BLM/BRD is the "proc ***" BLM. (Melee reference: WAR/Nothing)
You're there to get Green/Yellow/Pink/Whatever colour you want to call it. When you find the element, you nuke as much as you need, then ES -> Threnody if you still don't have it.

Your nukes will be laughable, but they'll get your job done. For more chances at landing Threnody* /BRD, you'll want to load up on Magic Accuracy+.

EDIT: * landing Threnody without the use of Elemental Seal

I'm by far not the best blm out there. I tend to be a traditionalist. My gear is mediocre at best, so I don't change subs to optimize crap. I'm a very casual player, a couple hours a night if that. Blm is the only job I know. I don't get into all the mathmatics of it though. I just don't care. If a piece of gear looks better stat-wise than what I've got on, or if I see a lot of blms wearing it, I'll get it (except for Goetia gear, Goetia seals are a GD myth I tell you).

That being said, take what I say or don't. I go /rdm outside of Abyssea for refresh, convert and fast cast. With atmas making refresh not an issue, I go /whm inside of Abyssea for reraise and to help cure. That's my only logic. No mathmatics, not really stat-based. Just simple reasoning. I don't have scholar leveled, I never thought of going /brd, and I don't have that leveled either. I'm just a simple girl who likes to blow ***up.

gotta find yerself a group that can proc and low man stuff. It's the Proc that seems to be the key on BLM and many RDM seals...NO Proc no drop, which sucks royally.

Manticor's, drop body pretty well....the hat and feet are a pain cause the drop rate sucks.

Please don't take that seriously....

Next update /sch will be hands down the best and only sub needed.

Do not try and get blm body seals off of Amarok it's a waste of gil and time....Teugghia is a *** but she's the best bet for seals

Random ***is random. We got 10 BLM seals in our first four or five Amarok pops while farming Orthrus.

Well from my experience with both I don't concur...not knowing cross server prices I can still pretty much guarantee cost/drop rate your better off with Teugghia

teugghia can be a real pain with a pickup group, but pops are cheaper. but amarok pops are more expensive because they're used for orthrus, which may or may not be useful to you.

The guy got his answer and isn't reading this anymore

This is precisely why we farmed Amarok, needed Orthrus.

That's nice, but given your low sample size I don't really care. Think about it: three NMs drop each seal, but there are four seals per NM. Balancing drop rates across that in any way other than simply making them all equal is unnecessary hassle for the devs and adds absolutely nothing of value. In fact, it's potentially detrimental.

If all you need is BLM seals and Teugghia is cheaper then by all means go for that, otherwise just go with the NM that best fits your other needs.