Hyperspace Is a Scary Place: It’s not so much hyperspace in the SFnal sense as the Void Between the Worlds, but the primordial chaos/cacoastrum of the bulk/plenum is, by and large, not a very scary place, because it invariably kills you before you have the opportunity to be scared. Its adjacentia, however, if anyone ever should manage to punch a hole in the universe, would almost certainly be utterly terrifying – the more so the more you understand about them.
(Well, okay, technically it doesn’t, but that’s because there’s no time outside the universe for there to be any instants of. But the effects of cacoastric exposure – to wit, dissolution/transformation into slightly less primordial chaos, with cake – amount to much the same thing, even if they happen at sausage squared over blue hadron teapot.)
Human Weapon: In some ways (and inserting obligatory not-human disclaimer), many members of the sentinel daressef would count, what with the various military-basic upgrades and then the possibility of various special upgrades on top of those. On the other hand, strongly averted because the Imperials are smart enough to treat weapons that are people as people first, in much the same way as they manage to avoid the AI revolution.
Humans Are Smelly: If there were any around, they would be.
But it’s hardly unique to them. All primitive species are: because it’s a consequence of advanced species (and especially those who take their cue from our friendly local aesthetes) investing in both much improved senses of smell plus excellent personal hygiene via biotechnology and nanotechnology. By the time you have skin that dirt literally won’t stick to, sweat that smells of roses and avoids supporting bacterial growth, and even shit that literally doesn’t stink… well, everyone not comparably enhanced is a stinky ape.
Or stinky lizard, stinky slime mold, stinky bunch of tentacles, whatever.
It is, however, considered polite not to point this out. It’s no sin to be primitive. Now, if it’s by choice, on the other hand…
Huge Holographic Head: Mostly averted, because while a perfectly trivial piece of image manipulation, even the usual suspects have long since figured out that it’s really hard to be taken seriously by people you’ve invited to stare right up your Huge Holographic Nostrils.
House Fey: While obviously not true in a literal sense, given the prevalence of AI house brains capable of self-development, houses tend to develop a fair bit of personality over time. And so, talking to the intelligence of a smart house with a few centuries or millennia of run-time under its belt can, on occasion, seem quite like dealing with a rather eccentric domovoi.
Hologram Projection Imperfection: As mentioned under the Hologram trope, their glamor failure is deliberate; trigraphic projections are splendidly perfect and accurate, and even can dynamically correct for lighting differences when used sender to receiver – so, unless otherwise called for, they’re deliberately tuned to slight transparency to clue people in that they aren’t solid objects.
NOTE: These are TROPES and or Fantasy Counterpart Culture ANALOGIES. No real cultures were harmed in the making of this fiction.
Hobos: Some individually-wandering members of the Traveling Houses (for more on which see Romani); while generally better off and by no means living a wealth-free life, even back in the day, some other aspects of the lifestyle and reason why one might take it up are similar.
Romani: The Traveling Houses do have some cultural elements in common with the traditional Fantasy Counterpart Culture – a nomadic lifestyle, for one, starting with caravans – although also barges and later, starships – but also have their differences. They’re not known/stereotyped for fortune-telling, for example, and are known for delivering the law (in the shape of wandering deemsters), education (in the shape of traveling teachers and new books), exotic speculative trade goods, and in some cases, the mail. And some members wander individually (hence the reference from Hobos).
And, of course, the Empire’s culture is much worse at sustaining wacky prejudices against people and altcultures who/which prefer to wander than to settle.