Since a rug under a dining table should be 4' wider and longer than the table top, yet not run into the wall,door or bar stools, you don't have space for one. The mirror is doubling the kitchen, not reflecting anything memorable, interesting or beautiful. Unless you find a striking chandelier that fills most of the mirror with its reflection and blocks the kitchen reflection, the mirror should go as well. Look for a linear chandy about the same length that the four pendants make.Consider the cleaning chore that kitchen residue will cause. Crystals would be a pain to clean. Since you need the slider open for light I'd suggest you install a cornice above it for fabric softness and some color or slight pattern. If you want drapery you may not have room for all of it to stack back on the left, and it will cover the light switches if on the right. You could add matching lumbar pillows to the deep backs of the chairs for more softness and comfort.

I was just looking at these patio door curtains online since I have a slider that needs drapes as well. They're about 100" wide and all one piece so they're easy to open and close. Hope this helps!

I can't see the chandelier that you have very clearly, but from what I can see I like it. The lines of it seem to fit well with the table.