"If the pic looks great at 100, 200 & 300%..."
You never have to go beyond 100% to check your image for noise, artifacts etc.
100% means just that...this is the image I present to you, and at 100% rez.
HA... I couldn't care less about rejection. LOL. In fact on another thread today I was telling the same to another MSG friend, take it in stride. Photos are like nachos, you can always make more. I was only curious about why magazines buy my work and a micro might shoot it down. I've had some of those rejected pix blown up full page in a magazine.
About my 100-300% comment. IS has required me to rework some images for trademark infringement purposes that you couldn't see unless you blew the pic up 200% or more. I don't know how the reviewer even saw some of them. Some of those same pix are on 9/10 other sites, the trademark never seen. Frankly, I didn't complain either, rather, I was impressed!
Keep those tips coming. They are appreciated.

-tom