I don't think the Dalish would be that welcoming of the offspring of one of their own and a human. Feynriel was an exception, partly because Marethari owed Hawke a favour and partly because of the fact that he was a dreamer and therefore his gift could be regarded as elven even if he was not. His mum did not originally belong to that clan; her clan rejected her. The Dalish may be willing to accept elves coming to them from the cities but they do not seem as forgiving of their own clan who choose to go the other way. This is logical because they do not regard city elves as true elves - only those who reject human culture and return to the old ways. So a clan member who rejects their culture, particularly to go with a human, is going to be an outcast.
In one of the city elf endings in DAO Soris marries a human and has to leave the alienage and goes to Highever (I think) where I believe it says he lived a happy life with his bride. We were told that when a marriage takes place of elves from different alienages both sides get something from it, either new blood or the dowry. I think Soris met with disapproval because his alienage gained nothing from his union, either in terms of new blood or wealth. The prejudice is partly understandable if the children of such a union are going to be human. If this became commonplace then the elves as a race would die out.
I would imagine that if a elf became pregnant as the result of rape, then the community might be less critical, since it would not be her fault. However, either sex choosing to mate with a human instead of with an elf would be seen as something of a betrayal, particularly since it would seem that their elders arrange partners for them.