I wanted this to be a comment on the answer below, but don't have enough points. In your question you asked how to set ILPIPs to multiple roles instances, yet your answer isn't clear if this is the full solution. Specifically, does the following seciton
<PublicIP name="FsClusterIp"/>
need to be duplicated (and assigned a unique name) for each instance of your FsService role? So for a deployment with three instances of FsService...
<PublicIP name="FsClusterIp1"/>
<PublicIP name="FsClusterIp2"/>
<PublicIP name="FsClusterIp3"/>
or is the solution simply as it is in your answer.
Did this work when deploying your service (roles) to an existing CLoud Service, or did you have to create a new Cloud Service when deploying.