You can use a trial account in SAP Cloud Platform to create a database using SAP Hana in-memory database. More information at How to use SAP HANA database on SAP Cloud Platform
More information on How to deploy an application to SAP Cloud Platform
No, GeneXus for SAP Systems can not open them, since it has not some required components (e.g. Database Reverse Engineering Tool, multiple DBMSes like SQL Server, Oracle, etc, .NET Generator,etc. ).
No, GeneXus 15 can not open them since GeneXus has not some required components (e.g. Fiori Pattern).
Contact http://genexus.com/sales and ask for a specific kit for SAP Systems development.
See SAC 41124
See SAC 41934
Use for each when none instead.