You can mount them without lifters, but you'll need shorter screws so you don't dimple/punch through the bases, or you'll need to grind your screws down. I have no idea what you're talking about regarding the brake digging in to the topsheet, never seen any issue like that. As far as ramp angle goes, it'll change unless you adjust the toe height to match, but chances are you won't notice it.
"Nothing is impossible. You are only limited by fear and even that you can overcome."