I think that although they look good on a thin attractive females (which everything does on a thin attractive female), they are not pants, they were not meant to be pants and they should not be thought of as pants.
Yoga pants are meant to be used for yoga and other sport activities, not as regular wear, tights are meant to be used as hosiery, and worn under something else.
Yes they are comfortable and people should be allowed to be comfortable, but that being said... would our society be accepting of men walking around with nothing but tights on? Most likely not!
So why should your camel toe, your ass crack, or any other part that is visible through your material be accepted simply because you feel like having vagina makes you entitled to wear and do what you want without question.
Simple answer... no. Have some respect for your damn self and stop assuming you have a right to be indecent while at the same time assume the right to shame those who notice your genitals showing.
It all depends upon top length. If you couldn't wear the top without pants then you shouldn't wear it with leggings. There's a few exceptions like if the shirt is just a little inappropriately short by itself, then the leggings can still be acceptable especially dark leggings that are thick enough to not be seen through.
Depends on the material. Don't be one of those girls that wear see-through ones. They have a lot of thicker ones now that it's become a trend to wear them out as regular pants. Get ones that are meant to be worn out.