Magnum force UCA

The install looks right. With stock UCAs, the rear mount is lower than the front but the ball joint pad is tilted to sit almost level. This is part of the stock "Anti-Dive" geometry that imparts some stress to the ball joint in the process of resisting compression under braking.

Regarding that nub under the arm, only trim it if it looks like it will make contact under full range of the suspension.