the 8-pointed star of chaos, other marines and imperial agents would shoot on sight at someone bearing the heretical symbol. No artificier would create such a blasphemous weapon or armor and if somehow the chapter gets away with all that Im sure the Inquisition has them under surveillance and suspicion for that symbol alone. but since its fan fiction you can do whatever you want.
It's clearly made to resemble a glowing star. That, along with the chapter's flawless service, should prevent outright hostility. As to being investigated by the Inquisition or whatever, everyone is.
I take critics pretty well, but there's a superior tone to many remarks on my 40k (a universe in which most things are arguable) drawings that gets harder to take with each new comentary. I pride myself on knowing the Warhammer 40000 setting, to an extent, so don't talk like I was an ignorant. The minimal nature of the majority of the mistakes I make should be enough to remind you that.