To me there are three things that make a manga, yaoi, shonen-ai or what have you, a good manga to read. I look for these things:
Content
Mechanics
Organization
Im a romance, angst, humor, action kind of person, I look for this content in my manga. The mechanics is how the story reads, if its a good one, if it makes sense, if I could get into it. Finally organization, is there a time line, a point. Its not either or, some people enjoy some people don稚, and for some its psychological. You read what you like or choose to read, right?
As for my parents, well since I live on my own they could care less what I do as long as I take care of myself. Its not like they punish me - though they look at me strangely sometimes
any decent parent would love you no matter what, I dont think what you read is an issue.