Congrats. Getting a new mount is better than Christmas. I'm a Mach2 owner so I'll allows others to address some of your 1100 specific questions
The CP4 will connect first via USB via the FTDI driver, from where I can configure ethernet (or Wifi, in my case to turn off).That will work, as will several other connection methods. I prefer serial over USB. You can run two cables for seamless backup.
CP4 -> APCC -> (Virtual ports) -> Ascom V2 -> third party software as neededThis is the order of operations for the CP5, so yes.
SkySafari is available on Android. It works very well with the CP5, so it will be great with the CP4 as well.