Re: tamper-proof screws aren't
"You don't even need that much torque. A couple passes with a needle file and they usually back right out like a normal screw."
Not if they are used correctly and If you managed it like that than they definitely weren't.
They should be countersunk to stop tampering with the head. They should also be torqued past the plastic deformation point so any serious force applied snaps the head off. For bonus points, make them harder than the case metal so a hand drill tends to skate sideways and break the bit.
Like all security measures, it comes down to how serious an attacker you need to keep out.