cyccommute 

Your cable may be too tight. But the problem can also be due to the front derailer geometry. Kind of hard to tell over the InterTubz. You should not make any adjustments to the limit screws! They have no influence other than how for in- or outboard the derailer travels.

As to your shift problems, as others have said this is common (less common than 35 years ago, however). Mountain bikers learn a technique where you ease up slightly on the pressure on the pedals when the front won’t shift. It’s just a slight reduction in pressure and becomes barely noticeable after a while. Modern teeth profiles help a lot too.

Gonna rant a little here: Front derailers are stupidly designed. Shimano had a chance to make them much better when they “invented” Rapid Fail but they chose the wrong derailer to work on. Shimano’s Rapid Fail was supposed to make the front and rear lever movement in the same direction. People often get confused about up and down shifts on front derailers (and some rear) because of the reverse action of the derailers. The front derailer relies on the spring to move the chain under heavy load and it isn’t up to the job.

Suntour make high normal front derailers…most rear derailers are high normal. In a high normal derailer, the cable is used to drag the chain to lower gears under a load…think of how well your rear derailer downshifts. Suntour’s high normal front dragged the chain off the chainwheels and shifts were quick, crisp, and, most importantly, it worked under load. If Shimano had made their fronts work that way instead of giving us Rapid Fail, they would have really revolutionized front shifting.

Instead, they fell flat on their faces. Nothing since U-brakes have been such a mistake.