You got skill mate.
Good job coming up with stuff, although the effect is certainly done before, I really like the card skill and your enthusiasm about what you do.
Nothing wrong with re-inventing the wheel, shows that your thinking which is a very good thing. Keep working stuff out and have fun with that. Don't come off saying "original" though, because you'll never know. Just say "worked it out" and all is good. Keep working things out, even if they may be not very original, inventing an original thing is very difficult these days even more experienced magicians. So, in other words, don't invent to show off to magicians that you made something original, invent so you can perform your own stuff that you created and enjoy performing them.
I know it can be very frustrating when told "work on presentation" when you don't have alot of ideas going on, because you didn't get to check alot of magic effects and different presentational ideas, as you go in magic you'll read more and more, and ideas will flow way easier. Don't force it, it will come automatically, if that makes any sense..
So, here's a tip on presentation: You may want to work it out so you produce the kings, get a selection, return the kings and completing the effect. This makes producing the kings more logical, rather than finding them, then losing them again.
Also, I think a turnover pass would be better.
Once you've done that, perform with pride. You got advice above to add originality to it or something like that, this might be very difficult for you right now, but as you go in magic more and see more effects you will make that on your own.
Learn walking before running. So for now, get as much performing experience as you can. The more you perform, the better you will be.
I wouldn't even say master routining or anything, this will be later on on a later stage. For now, you do the sleights well ( except the last one, do a turnover instead ), perform and get experience performing. Thats the most important thing for now.
Cheers,