[@Dead Cruiser] Kira was already dead, but Cheap Trick is a fair argument (though it could be said that he was also sort of dead after killing his original User). Still, the ghosts of the alley are... pretty bullshit canonically, considering what they actually supposedly do to Kira.

That "special club" thing is kind-of a nonargument in the face of Merlin's magic (which no-one else has), Ben's hilariously versatile options, Danny's powers also being their own thing and extremely versatile/extensive besides, and Terra (who needs no further explanation). That said, as I generally tried to convey, I've no issue as long as it makes sense. Stands are a projection of the soul; by that logic, only things that can sense/affect the soul/spirit should be applicable, even if it isn't another Stand. That, at least, makes sense. And sure, poor Jason is kind of in a pickle... but that goes for nearly every other match-up he could have.

That aside, despite any possible illusion to the contrary, Bruno is not anywhere close to indomitable, especially if he's being played in-character and not OOC munchkinned (though he is very much a canonical munchkin with his ability). Unlike the rest of his compatriots, he is fully human with all the inherent weaknesses. He has no special defenses against exotic/unknown abilities. He cannot heal or breathe in space. He's not unageing or immortal by any definition of the word. His Stand is also not automatic or a passive defense, nor does he canonically demonstrate any notable proficiency for some of the more exploitable universal Stand abilities, like selective tangibility. Taking both his personality and the RP's location into account, he's actually fairly vulnerable by comparison. He can and has been caught off guard to lethal effect canonically, even if he was able to make a come-back. 

Stands not being genetic? They kind of are, spiritually so sure, but that is definitely the case. The issue is that the only family we really interact with is the Joestars, Okayasu and his brother, and Pucci and his brother, so there's limited exposure to other examples. But I don't recall a case of siblings/family displayed where they didn't all have Stands if they were descended from someone with one. All of the above examples either got a Stand from an arrow directly or inherited it due to spiritual genetics. The Joestars aren't some exception to the rule even with Fate hounding them.