Yes, a lot of mice allow you to increase your DPI, so that you can get rid of pixel skipping. Some say that the gaming mice have amazing sensors, well that's not entirely true. You really won't notice a difference. Standard mice come shipped with 125 Hz *polling* rate at 800 DPI, when people are buying gaming mice, majority of them lower the DPI, basically putting themselves at an disadvantage. The difference is the feel of the mouse, and the weight. A "gaming" mouse won't make a bad player good, or make a good player bad. It's all in each induviduals muscle memory, regardless what setting you use, and regardless which mouse you use, it's always you, and not the mouse.
"Gaming" keyboards are typically marketed with cherry mx switches or similar switches, while they claim you'll respond faster, your in-game latency, your computer, and your actual reaction times makes this number obsolete. These switches do however change the feel of it when typing. Some people play better with dome keys, some play better with "gaming" switches. It's really just preference.