Hi,
1) four channle's interrupt requests are ored into single vector in eMIOS and EMIOS0_0_IRQn belongs to channels 23,22,21,20
2) it is in S32K3xx_interrupt_map.xlsx attached to the RM, also visible in project
PetrS_0-1672993794891.png
3-4) priority is set either in the component you shown or a IntCtrl_Ip_SetPriority function can be used, i think.
BR, Petr