Hi Juan ,
you can use Remote APIs to call the process from your application and the information can be found in this place RemoteAPI Guide there are different ways we can adopt. if you read the guide you will get info and also you can choose which works best for your case.
Secondly Security Aspect I will try to explain but may be it is not the complete answer. I can provide you some guidelines. as you see that all the example application uses EAP/WILDFLY user.properties and roles.properties which are configured to the security model of the Application server and configured into those file. If you think you want to secure kie war i.e. kie engine deployed then it will have to be secured in the same way as any other application you would like to do . Lets say you want to loop up in LDAP or some other place where you keep your security information . Then you will have to create the security Realm and plugin and configure back into the EAP/wildfly security configurations. I believe you should read the EAP security guide where you can configure the Custom Securtiy Realms.
I hope it help a bit . I believe more experts on this may provide more to the point answer.