Follow IPC-2221 series recommendations.
In lieu of IPC-2221: I see a lot of 'D' shaped hardware pads.  They work just fine.  Working from IPC, keep copper a minimum of 20 mils (0,5mm) from edges for ground features and mounting pads.  Try to keep traces and power planes further away than this.  Also, if using v-scoring, add another 20 mils (0,5mm) of edge clearance to accommodate the scoring.  Also, see the previous discussion on components violating the 5mm clearance (minimally pre-rout to relieve stress during shear or set up to rout the assembly.  This is especially true if PCB is conformally coated as rotary shears do not deal well with coating in the v-grooves.

A very good rule on hardware interference is 125% times the largest diameter centered in the hole approximates the cumulative tolerances and shifts that can occur.  Also, use 'N' (narrow) hardware where possible if spacing is tight.