For example, given a cluster of 3 members, if a webapp container is spawned on member1 of the cluster and member1 is subsequently shut down, will the web app container automatically restart on another member of the cluster? Or to achieve this redundancy, do i need to manually launch the container on each member during setup?
Short answer: no it wont do it for you, you have to manually do it
Longer answer: Its a little more complicated than just moving it over because of storage, external load balancers ETC - you dont indicate if you are using CEPH for distribute storage amongst the nodes but this will also impact your ability to-do this (to some extent)