Lol, I see a repeat of the bst nerf coming to smn. Yes your BP's do squat damage now, but we gave you a new summon; Chocobo!. He runs out and lays an egg, and 5 minutes later out pop fireworks.
Smn is the hardest job to level to 75 and mnk gets the shaft in gear upgrades? If you want to argue semantics I guess you could say mnk gets the shaft in upgrades, since they get the majority of their elite gear 34-40. But smn is the hardest job to level? As long as their is a shortage of whms, smn will always have "we couldn't find a whm, wanna exp?" How often do parties sit in jeuno looking for a healer? How often do parties sit in jeuno looking for a melee DD? You can say your job in exp parties is harder, but getting to 75 is much easier, since you actually get those exp parties.
I honestly don't see smn fitting into lvl 3 SC's, except their current spot (Retribution!) Level 70 BP's do so much damage, you couldn't fit them into a SC without making smn the most powerful DD 70+ by far. If you got some other BP's that chained, I wouldn't expect them to be any more powerful than a 215+ ws.
Every job is getting merit spells/abilities at 75, smn won't be the only job. It's gonna be one of those perks for end game, and will end up driving out some of the non-75's from end game activities.