Just don't worry about what others like and what you would want to hear from a rapper and become that. Don't try to bite a style because you think it sounds nice though, just be yourself because you can only improve yourself, not others, if you feel me lol.
When you're working on delivery, just imagine you're talking to someone, and you're really trying to get a point across.
Flow is subjective to the style of the beat, all you can really do is upgrade your vocabulary so you have more words to work with.
Wordplay is the comic relief to the whole act. For me, wordplay comes to me most easily when I'm truly having fun making music. I don't know if that might apply to you, but you could try it.
Just remember that making music should be fun and should come easy. Don't think too hard about it because it still is an art, and the magnitude of your art is always truly subjective to the eye of the beholder.
This applies to anything it's universally accepted that confidence and intelligence in your field is an advantage. Your music is talking to people, so you're in the people business if it helps to look at it like that. What you say is going to speak to people either positively or negatively depending on how you go about what you say.
I'm assuming you're still in the beginner stage of rapping. If I were you, I would write down everything you come up with, even if you're not too confident about it, just to get it out of your mind, so you can move on to the next set of lines. Just keep practicing and writing and spitting over every beat because you'll only get better. Don't worry if you think you sound ridiculous because everyone goes through that stage. You're subconsciously fixing your flow every time you spit over a track.
Good luck!