That's the problem. Doing that could put the remaining Sword in his care, plus the other relics in danger since he is their caretaker. So it isn't as simple as that I don't think.
The sword is only in danger if you use it improperly. He's done lots of violence while their caretaker before and they were just fine. He didn't have to become a pacifist to be their caretaker.
Don't know of coins can change genders, so I think Thomas and Eb are safe.
... Huh? Lasciel is identified as female and we spend five books watching her try to get Harry to partner with her.
Lasciel was distinctly female... We don't know the gender of Deidre's Fallen one.
Mira, Foxed is pointing out that Lasciel, a distinctly female Fallen, has been trying to recruit Harry, a distinctly male wizard, for literally years, so there is no question about gender being an issue. It obviously is not.