Re: install fedora 23 on imac
Use 'dd' to write the ISO file to a USB stick. If this is on OS X, it'll go faster if you use a block size of 32K or bigger, e.g. bs=256K, and also write to the raw device for the USB stick, i.e. /dev/rdiskX rather than /dev/diskX.
If you're OK using default partitioning, the installer UI makes it pretty easy to "delete all" to free up the entire drive space by deleting all partitions.
The two things I suggest, add thermald from the COPR repository, and then:
systemctl enable powertop
systemctl enable thermald
Thermald you can use right away, you could hold off on enabling powertop until you have some experience with Fedora behavior on your laptop. For example on mine, I'm currently suspicious the optimization from powertop is causing wired ethernet to not wake up when the laptop wakes from sleep.