best way to push new IIS sites with zero downtime?

Yes that looks to be the way to go. I was told from others to setup two pools and just switch the default pool. I haven't found any docs recommending that though. One problem with that is you'll have to go into each virtual server and change the default pool. For application that have multiple servers, this could created problems for obvious reasons.

Being that we'll have a virtual server for http, one for https and virtual server another for two other TCP ports, I assume I can just have all of these virtual servers use the same pool. Once I deploy new code to my passive server, I'll enable it in the pool and force offline the server I want to bring down. The server with the new code will receive all the new connections and it should be pretty seamless for the end user.

Sound good?