When I use my elliptical at home, sometimes I'll use my crosstraininers and sometimes my runners if I happen to have them on and I find that since your feet never really leave the pads and there is no impact, I feel that any shoes that are comfortable should be okay. Enjoy your elliptical!
I use my cross trainers on the elliptical, mainly to preserve the life of my running shoes since I use them more frequently than my cross trainers.
As to your toes getting numb, are your laces too tight in the toe box on that particular foot? Or perhaps you are putting more weight/pressure on that part of your foot when you are on the elliptical? I often have to check myself on the elliptical to make sure that I am distributing my weight evenly on my feet.
I've loosened my laces and that helped some. I'll have to pay attention to my weight distribution. I do tend to favor my right side a bit, well maybe a lot. thanks for the tip.