1. Slightly but not sufficiently. It would be highly interesting to learn more about why exactly mankind worries so much about the supermen when there's a whole galaxy full of threats out there.
Sure, having eighty Napoleons on the loose is unnerving - but at the time of "Space Seed", there were more than eighty Nazi leaders of similar standing on the loose, and that worried very few of us. And some people being decidedly superior to others has always been a source of inspiration (see sports) rather than fear, at least for the cultures that continue to rule Earth in the TOS era.
The Augments of ENT offer more of the same: supermen out of their environment, struggling to regain a status in a world that no longer dances to their tune. An alternate viewpoint would have been of greater interest.
2. Much as with NOMAD, I guess the security detail is there for symbolic purposes, relying on the captive honoring his terms of captivity. As with NOMAD, that's all that's holding the captive back: the guns and the manpower are no obstacle to him breaking loose again.
I'm not sure whether Montalban and the director could have pulled off the choreography of Khan disarming a security force that pointed guns at him from a reasonably safe standoff distance. Yet that's what the superman ought to have been capable of doing, what with being credited with superiority in so many fields: speed, strength and the cunning to make those count.
Timo Saloniemi