I think your mantis is fine, just tried to track prey through the side of her/his cage, and rubbed his eye on the side of the cage. I have a Tenodera that has the same problem.
I think your mantis is fine, one of my mantids had a spot on his eye after a molt. The next molt is was gone. Your mantis is not an adult yet, so maybe the next molt it will be gone too.
That is normal. Feeding it once a day should be fine, but don't worry about keeping a strict feeding schedule;it is ok to miss a day or two if he is getting fat. It is definitely a Stagmomantis sp.
yup i got it away from my job and let it go around my apartment just put 3 small crickets and a medium one i think it got the medium one lol he looks full