For the health care camera case: "The MV12W, with its fixed wide lens, is typically sufficient for providing an overall view of a typical patient room (15 x 15 feet). The MV12N may be considered when the desired field of view is smaller (for example, a hallway or a narrower room)."
I'll give a different viewpoint. I tend to tell clients to use the wide-view MV12 when installing on a wall (so there is a potential 180-degree view), and the narrow view MV12 when installing in a corner (where there is a potential 90 degree view).
Not much point using the wide view MV12 in a corner ...
It's been a while since I had to do a serious multicast project, but my recollection is the RP should go on the L3 switch nearest the source of the multicast streams - and not the core switch (it could be the core switch if the major sources directly plug in there).
This becomes more crucial when there are multiple paths in the network. You typically want the shortest path from the origin to the client. PIM builds the shortest path from the RP. So if the RP is not right next to the source you can get all sorts of non-optimal multicast routing happening.