[Slono]

The steel casing you're referring to is called the blowback unit. To solve this problem you will have to file the bottom where it makes contact with the frame of your gun. Once it is sanded so it fits flush along the bottom of the slide, then it will slide with less resistance. A little bit of grease will help too. I use white lithium grease because its easy to find and a small tube will last you years. All you need is a tiny amount on your finger to spread on the parts that make contact.

With regards to the outer barrel lugs not lining up properly against your slide, this could create a couple issues. Because your loading nozzle is designed make a seal while mating with the hop up rubber, if the whole hop up assembly is sitting farther forward it would potentially ruin the seal between the hop up rubber and your loading nozzle. This means that the path of the propane that eventually hits the BB is going to be inefficient and will result in power loss. Think of it like a garden hose that's sprung a leak... the pressure at the end of the hose will be less than if you had a garden hose that did not have a leak.

One other issue that may be causing your jam is the bump on the underside of your blowback unit. If this bump catches TOO MUCH on the tip of the hammer it will prevent your slide from returning to its normal resting position. To fix this you can either file the tip if your hammer at an angle to help it overcome the bump on the blowback unit or you can file the bump on the blowback unit. Either way you want to file or sand it just enough that the slide can do the rest of the work itself. If you file too much material off your gun won't function properly.

If you post a video or some pictures it would definitely help with this process.