It's all about grip. Bare feet and socks can slip off the pedals, but so can certain types of foot wear. A pair of sneakers works fine. If you do take of your shoes, don't stow them right by your feet cause they tend to get under the pedals. As far as feel goes, bare feet can amplify the rubber road feeling, but it's not really needed unless your in competitive driving. If you can't feel the the friction point of the clutch by car momentum, the ABS under hard braking, or slip of the tires in acceleration, then either the soles of your shoes are to thick or just need more practice. But other than the hard braking or acceleration, when is that needed for day to day driving. Be comfortable, but not to the point your complacent. Just get a good pair of good fitting sneakers and call it a day.