Hi Andreas,
according to the SAP S/4HANA Roadmap Edition 2015Q2 (Page 14, SAP Service Marketplace access required) the co-deployment of SAP Customer Relationship Management (CRM) on SAP S/4HANA On-premise as an Add-On is a Planned innovation. You should also check out the OpenSAP course SAP S/4HANA – Deep Dive - SAP S/4HANA experts where there is also a discussion and some answers to your questions: https://open.sap.com/courses/s4h2/pinboard?question_filter_order=activity&question_search_string=crm
Best regards
Gregor