How should I sew my binding for a wall quilt? Is it better to do slip stitching or blind stitching?

I do the same binding for a wall quilt as for any other quilt. The only thing I may do differently would be single-fold vs. double-fold for a small quilt.

whichever you prefer.

How about the thread? I'm using a 50wt cotton machine embroidery thread. Will that be fine?

I can't see why that wouldn't work.

I haven't noticed any difference in what I use on mine. I hope this doesnt come back to haunt me!

No quilt police on that -- do what makes you feel comfortable. It won't get as much wear as a quilt.......so finer thread would be okay.

I'm just being paranoid. But are blind stitches as secure as slip stitches and vice versa? I find it easier to do blind stitching and would prefer to sew my binding this way.

I like blind stitching on my binding. It's held up just fine for me so far. Go for it.