I think we each are far more aware of the bumps and imperfections on our own feet than anyone else will ever be. Until I started wearing sandals two years ago, I thought my feet were too weird and ugly. I do try to keep my nails clipped neatly, but I also don't wear polish, and I always have huge calluses, abrasions, and injured toenails from dancing, plus a mild deformity in my instep that results in a big bump on each foot that is always red from pressure from my shoes.
Now I just think they're feet. I agree with everyone who thinks that it's fine to show imperfect feet. But I do also sympathize with being reluctant to show them.
My only-tangentially-related story, aka, porn toes:
When I started Irish step dance five years ago, I banged my big toe hard and the whole nail turned black. It took about a year to grow out. Meanwhile, I'd just bought my first sandals and I felt weird showing the big black toenail. One night I was at a party and mentioned my predicament. A friend of a friend had nail polish in her purse and offered to paint my toenails. The polish was bright fire engine red - actually, this woman is an, er, adult actress, and this was what she'd brought to work that day for a photo shoot!
The next morning I decided to wear my sandals. I felt SO self-conscious. It felt like my toes were as bright a beacon as Rudolph's nose. Then I remembered I was scheduled to meet with my advisor, a very famous scientist in his 50s. He's the type who wears running gear to work every day. As I walked to his office I tried to reassure myself that my toenails were totally normal, that everyone else wears nail polish all the time, that he certainly wouldn't notice. (Also, technically, I shouldn't have been wearing shorts and sandals in lab, though everyone always did.) Combined with my usual anxiety about meeting with him, it was quite literally enough to make me skip the meeting, but I made myself go.
And of course, the very first thing he said was "nice toenail polish!" After a few seconds of mortification, I realized that had broken the ice and it didn't seem so ridiculous any more, though I bumbled my way through some sort of unnecessary explanation / justification.