Configure Or event in process model, validate multiple if conditions

Yes, you can define whatever functionality you want in the condition fields of an XOR gateway.  Any expression that ultimately evaluates to TRUE or FALSE is subject to be used in the XOR output path expressions, and they're evaluated in order.  In these, you can combine any other logic you want, using expression logic including but not limited to or(), and(), if(), etc.

Yes, you can define whatever functionality you want in the condition fields of an XOR gateway.  Any expression that ultimately evaluates to TRUE or FALSE is subject to be used in the XOR output path expressions, and they're evaluated in order.  In these, you can combine any other logic you want, using expression logic including but not limited to or(), and(), if(), etc.