those examples are using trade offs to accomplish the over the PL limit for defense and attack.
Keep in mind:
Defense affects your Toughness inversely and vice versa.
Attack affects your Save DC bonus inversely and vice versa.
Weapons Master:
Defense 14 means that her cap for her toughness is reduced by 4 becoming 6. This also limits her CON bonus to a +6 as well.
Melee or Ranged attack 12 means that the max Save DC bonus is reduced by 2 becoming 8. Note that it says melee OR ranged, you get the appropriate one based on if you choose blast or strike as her device's power, so if the power is strike her Melee attack is +12 and her ranged is +8, reverse that for picking blast. BTW this trade off limits her STR bonus to a +8.
The reason that her attack was bought to a +8 and then either ranged or melee is increased to +12 is because it's cheaper to raise just your melee or ranged using the attack focus feat. If you want to be equally effective just pay for the attack you want without using attack focus.
So when she uses her device she adds +12 to the attack roll but can only add 8 to the damage save for her device.
Speester:
The speedster has a defense bonus of +15 which means the max that his toughness can be is +5. The max he could get by increasing his CON is +5 and this effectively limits his CON bonus to +5 as well or a CON of 20. The build only bought a CON bonus of +2 which kind of hides the trade off.
In short if you see something over PL assume a trade off even if the reduced value wasn't purchased at max value.
A good place for help is
www.atomicthinktank.com.
HTH,
Gil