Hm, the first concern I would have is: Even if it didn't happen in the past during some situations for any of them, does that make 'no feelings possible to attach' a rule? It could be different from person to person they meet or get involved with. I know that some are able to separate sex and feelings (I am not, at least the sex doesn't feel that good without feelings, but never mind, I am not some kind of standard). But I would never assume some kind of guarantee that there will never develop something between them just because of that.
The second point coming to mind is this 'healer attitude'. Yes, there are nice men out there. Yes, shying away from all physical or intimate contact for life would be unhealthy. But this kind of sounds therapeutic and he isn't some kind of professional or something like that. So if the friend feels the need to overcome some fears, I would look elsewhere.
I wouldn't feel OK with this situation personally.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.