Going down any stairs should not be that bad if you have decent shoes.
Flats are icky looking, and I have to agree with Manda. If you want flat-soled things, there are sneakers, trainers, athletic shoes, Burks, Docs, Chacos, and even Tevas.
Also, jesus, did no one else see
Kinky Boots? Heels do change how you look: they elongate the leg, accentuate the calf (and make the leg look more curvy), and cause the pelvis to tilt. I believe the line is "Look to the heel. The sex is in the heel ... Stilettos require constant balance from the upper leg causing the muscles of the backside to tense and appear pert and ready for mating".