TIDA-01606: UCC5320S schematic question

Part Number:TIDA-01606

Hi,

I have several questions for the schematic below:

1. why need 10ohm(R33) for the primary side 3V3, but not needed at the secondary side 12V and -5V? And why R33 is chosen to be 10ohm?

2. R10 and R50 are both 0ohm, I guess only one will be soldered in the final board, right?

If we solder R50, then there will be no negative power  supply at VEE2. Then do we still need C42, C43?

3. Why R36 and R39 are 3.3ohm? Is it chosen by calculation or by trying different value on the real board?

4. In this board we are driving IGBT with UCC5320. Are there anything different need to pay attention if we are driving SICFET? From both schematic and PCB layout point of view.