If it's a shoe to protect one's feet but not for walking around much and worn only a couple of times previously, sounds okay.

Where I draw the line for myself, is to look at the whole undersole/heel of the shoes and see how it's worn down. I cannot bring myself to wear and walk around other people's shoes, particularily worn down even abit because my gait and weight pressure on how shoes get worn down will not match to another person's gait and how shoe is worn down.

I wear customized orthotics even in cycling shoes...hence, have no intention of undermining its great corrective benefits to my feet, and posture by wearing shoes that aren't worn down at the heel/sole in same way as my feet.

Sounds picky, but customized orthotics are hundreds of $$ --more than cycling shoes.