The selfishness of humanity for sure, and I believe the harmony of life after death, I'm not 100 percent sure about that one.
Answer:
For the first one, Romeo is trying to say that love is all different things, it can be happy, lonely, exciting, and sad. But that he wants that and yet believes he won't ever find it.
Explanation: I do not know about the second one, sorry. Hope this helped tho! :)