IGBT Inverter

[MOSFET KILLER]

I am building a very large SMPS and need to build an inverter. The inverter I have designed uses 4 HGTG30N60B3D IGBTs Fig.1. I have to build a device to drive the gates of these IGBTs as well as protect them in the event of a short circuit.
Now for the design of this project.

1. I have recently read an article discussing gate resistors on IGBTs and MOSFETs to turn them off faster, how can I calculate the value of the gate resistor?

2. I have designed a PWM circuit that outputs the signal shown in Fig.2, how can I use this signal to drive the gates of the IGBTs?

3. I want to design a short circuit detector for the collector and emitter of the IGBTs to turn them off in the event of a short circuit. How can I build a short circuit detector?

4. I know that these IGBTs have a turn on gate charge, how can I find out how many amps this will draw to turn on the IGBT?

5. The high side driver of the circuit is going to need to be transformer coupled to the PWM to prevent the supply from shorting out through the driver, this will require a comparator. How can I use the open collector to drive the gates.

6. When I turn the IGBTs off will they need biasing to turn off faster, if so how can I build a device to bias them during turn off.

Any help will be greatly appreciated.