Sorry to burst the bubble of your entire premise, but "Every solution to the Tenpenny quest ends in murder" is wrong, full stop.

I finally made it through the quest yesterday, and though it certainly takes some finagling (and possibly high enough Speech skill), you can convince the Tower's most bigoted holdouts to let the ghouls move in, then convince Roy that all will be well, and you've got your true happy ending.

The bigots are duly angry at you for masterminding the situation, but nobody dies (apart from the usual ferals), and the next time you enter the towers it's teeming with polite, sharp-dressed and fully integrated ghouls wandering the lobby and suites.