You can run any number of apps you want on the PI, as long as you have free RAM, disk space and CPU time. The tricky part will be getting all of them installed and configured to your liking.
The easiest way to run something on your PI is to download an OS image. You obviously get only one app this way.
The other way is to install a base distribution (like Raspbian) and then install any number of applications.
Obviously the third way is to start with OS image with some app installed for you and then add the rest of the applications. The hardest thing to get running is a chromecast / MiracleCast "emulation".
I know of at least two distributions of Kodi and because it is really multiple applications configured together (hard to get right initially) I would recommend you to start with that. Once you have Kodi running to your liking make a backup of the SD card. After that try installing each and every additional app you like. If something breaks - restore the backup and try again :-) I am not familiar with pi-hole, but it looks like you must download an installer and run it (most likely as root)... piece of cake. Luck!