If that is what makes you comfortable then yes why not? What is important is how you feel about what you wear. For me I wouldn't like it. I own and wear black tops and trousers but never together and I really do not like the synthetic leather look, especially in leggings or leopard print as to me it looks tacky but I have seen my friends pull it off quite nicely. It just doesn't suit me. I am very much the jeans wearing dark or light with a top that contrasts against it (so a light top to a dark trouser and visa versa) with some shoes to match the top and accessories for it all. Apart from when I am just at home. That is when I just sling on whatever for a day.
Yes It's definitely okay
Yes its looks to good
For me,yes... Try adding some details over your clothes. :)
its fine, looks terrible
It will look pretty
Of course its ok, but accessorizing with pops of color or patters are usually what completes an all black outfit.
yes.