Mobility affects your walking and strafing speed as well as max height from your first jump. Also affects cooldown on Hunter dodge. Resilience affects how much damage take before dying. Also affects cooldown on Titan barricade. Recovery affects how fast your start health and shield regeneration. Also affects cooldown on Warlock rift. As for guns: Impact is self-explanatory: how much damage a weapon does on hit. Varies by weapon archetypes and is affected by range drop-off. Range is how far out a weapons deals consistent damage before experiencing drop-off. Example: Adaptive HCs usually hover around 30-35 meters. Anything farther, they start doing less damage. It also affects aim assist in some way. Stability affects how hard a gun kicks when fired. Higher the stat, the less it kicks. Recoil direction determines in what direction a gun kicks when fired. Even if you have max stability, low recoil direction will still pull the gun in a certain direction. (If recoil direction ends in a 5, recoil is almost entirely vertical, which is what you wanna aim for.) Handling affects how quickly you: aim, pull and stow a weapon. Snapshot sights basically gives you max handling just for aim. Quickdraw is universal handling for like second or so. Reload is self-explanatory. Outlaw and Field prep provide the fastest reload times for gun perks. Hope that helps.