brake pad loose in caliper, replace fitting kit, check for missing spring shim.
not usually. warped rotors will cause a vibration during braking.
What percent of braking are front wheels responsible
To the FRONT of the vehicle
My guess would be that you might have a bad brake hose to one of the front calipers.
Your rotors are probably warped from getting hot during braking and need to be "turned" or replaced. I suggest you take it to a brake shop or dealer.
Dual diagonal braking is where the brakes are on two systems right front and left rear as well as left front and right rear. This is to give even braking in a partial system failure
I beleave it's Front 60% and Rear 40% that is distributed between them both
The front brake pads have wear indicators that will cause a squealing noise during braking when the pads need replacement. If you don't have this noise during braking they don't need replaced. Rear pads should last through 2-3 sets of front pads. The brake fluid should be replaced every three years.
Possibly a rotor scored badly or warped from overheating, maybe a piston that's sticking. Either way, essential to strip the front brakes and check everything.
bad front brakes.
Probably braking hard.
70/30 % front/rear