They have very similar meanings. "Death-mark'd love" is pretty self explanatory, and "star-cross'd lovers" are lovers that are fated for doom. This basically foreshadows the fate of Romeo and Juliet and what will likely happen to them due to their forbidden love. Unfortunately I don't have the prologue on me nor did I read it in a very long time, so I can't provide evidence. But that's basically what it is trying to say.
Well, for starters if the parents start hitting the child because of the lack of peace from stress then that would be considered physical abuse. However, if the parents abuses the child mentally by saying harsh things then that’s mental abuse. So, to answer your question, this would be considered as mental abuse. This will affect the child to be much more afraid in life if they do something wrong and it could also affect the way that they treat their future kids. Then, there would be a pattern on and on and this would never stop unless they seek help.
I hope this answer helps!
Are there answer options?
You need to identify the characteristics so that it is easier for you to hunt them, (if they aren't endangered). You would have better experience between all of this and it would just be simple for you. :)
I would say A for question 4