Inhumans vs. Morlocks: Morlocks have existed for decades, the Inhumans have been around for Millenia. They aren't Human, they arent mutants, they are early humans who've been tampered with so they're essentially immortal. Morlocks are just Ugly Mutants who live in the sewers. One's a royal family, the other's just an underground society of the ugly side of Mutants.
The Watcher: I think he should not be involved with SHIELD, but be someone SHIELD tries to work with. Like he's the Ultimate Hacker, he knows everything because he's broken into every government database in existance. The US Gov doesnt persecute because SHIELD can get information out of him. I do think he should be a big deal if he's done like that.... just no Moon Headquarters... or disproportioned heads... or anything like that... At all...