Imo, as long as he remembers what emotions are supposed to feel like, and views the Shinoa squad as persons instead of bloodbags, he should be OK, I think, for a vampire anyway. Though it will require constant hard work on his part and a lot of determination, like even if he doesn’t care, he will have to force himself to at least try to care, to always control himself and adjust his actions to a higher moral code (like, he may not care about saving someone, but he has to have awareness that it is wrong to leave them to die, resulting in him going saving them anyway). Crowley still seems to find children’s blood something of a taboo for himself unlike so many other vampires that love precisely children’s blood, so I believe it’s possible for some lines not to be crossed to remain and for moral guidelines to be preserved to a good degree, they just need to be constantly actively maintained (and, well, they have to exist in the first place… it seems to me that not all the vamps had them to begin with when they were human…).