Last Mile. You might try checking the Hammer face and the part of the slide that contacts the hammer. Make sure both surfaces are as smooth as possible. I don't know if the bottom corner of the slide face can be rounded a litlle bit or not. If it can be radiused slightly this may help. Be carefull how much you do. I would have to pull apart my buckmark and look at it to see what else might be affected by this modification. Smoothing everything though should be OK.
Dry firing any gun is hard on it's internal parts. Harder on some models than others. All guns can take a limited amount of dry firing without any damage. It is always wise to point it in a safe direction and release the hammer prior to storing any firearm.
Centerfire firing pins do not impact directly on anything if you pull the trigger on an empty chamber. The only impacts are usually to the sides of the firing pin hole in the breach face. When dry fired repeatedly on early firearms, this area could be "peened" to the point the metal around the fireing pin hole would actually start to stick out, or weaken or crack. This could cause all sorts of problems. It could also weaken the firing pin to the point where it would break. Modern steals being what they are, this is much less of a problem today, however, if you are going to dry fire alot, such as the "snapping in" that competitive shooters do, you should buy some snap caps. Dry firing once before you put the pistol away, will not apreciable reduce the life of the firearm even if you go to the range once a day, every day, for several years.
RIMFIRE arms are a different story. That is because the hammer is offset so that it will pinch a section of the cartridge rim between the firing pin and the breach face, (shoulder of the chamber.) If there is no cartridge, the steal firing pin will strike the steal breach. This will eventually damage the chamber, the firing pin or both. A lot of modern designs utilize a cross pin through the firing pin that limits how far the firing pin can protrude. The idea being to keep the Firing pin from extending far enough to hit the breach face. The idea has its limits although it does allow you to drop the hammer on an empty chamber before you store the firarm, I wouldn't use it to do a lot of dry firing.
In the long run, if you want to dry fire a lot, the best way is rpobably with a revolver and snap caps. Autos can use them too but they are something of a pain as each time you cycle the slide you have to reinsert the snap cap or keep putting them back in the magazine. I've seen folks remove the extractors of pistols so they could snap in, with out messing with the snapcap. I know of one person who made "dry fire only" firing pins for a 1911 out of a stiff plastic piece with a section of rubber on the end that the hammer struck. Very nice design that cusioned the hammer blow and wouldn't cause any damage to the breach. But revolvers are still easier to work with.