It's normal to feel the hangup when riding the slide. You need to replace the recoil spring for the problem when firing. You can get recoil springs from the Glock web site store for $5.00. Brownell, and MudwayUSA have them for like $7.50.
Is the slide hanging up under full spring power or are is it hanging up when you hand ride the slide? In other words easing the slide forward with your hand.
Once I put a new battery in my C-More it worked much better and brighter. I could actually aquire the dot much faster. That's my excuse and I'm sticking to it.