Guys are attracted to the legs more than likely because it is the part of the body that attaches to the butt. They are curvey and usually smooth. Girls wear shorter shorts and reveal more so guys are more accustomed to seeing legs than girls who at most see guys legs up to the knee. Not to mention they do not shave their legs.
If girls tell you that your legs are cute and guys make fun of them, the guys may be jealous of your cute legs.
men have longer legs
If guys make fun of your good looking legs they are probably jealous that the girls like them.
Some do
Theoretically if you are taller on average your legs will be longer on average and vice versa if you are shorter. Also but still theoretically if you move longer legs and shorter legs at the same time with the force to scale longer legs will travel more distance in less time than shorter legs. However this is not completely true if you account for the fitness of the person or the fact that the legs will not be moved with a to scale amount of force.
because they are fat and skinny
may be you have thin legs
Yes, usually most guys do though sometimes they do not
because they get nevous
Chickens with legs and buts
Some do, most don't.