I think the applique would look lovely, and really enhance the quilt top.
I just have to say this - and I mean no offense - but before you do the applique, please make sure your borders are correctly attached and the correct length....I don't know if it's the picture, but it looks like there is a lot of extra fullness in there.
As you said in your post, you did the sampler blocks to work on some skills. Learning how to properly measure and attach borders is soooooo important. I really can't stress it enough.
I would hate for you to do all that beautiful applique, quilt the quilt, and find out your borders have the topography of the Rocky Mountains. You can't go back and fix it later.
A sampler quilt book might have very generic instructions. I'm sure you can do a search on the board - I did very quickly, but some of the suggestions weren't great, and could lead to even wavier borders. It's so important to understand how do to it correctly.
Feel free to PM me if you want, and I can write out the correct way to do it, and post it here. But you don't just slap them on and sew, not after all that hard work.