You will need to put a gateway after the Rule Task so you can decide which path to follow. Inside your rules yo will need to set 1 or more process variables, then you can us those variables in the gateway to make a decision.
Regarding ksession.fireAllRules(), there is another way to do this, but at the moment that other way (ksession.fireUntilHalt()) causes some other problems related to timers and persistence. So, my advice would be to continue using ksession.fireAllRules().