I just swapped ubuntu for fedora on my macbook air and the setup for that was super, super easy. With ubuntu I needed refind, but fedora shows up right in the OSX bootloader. On my desktop I use separate drives so I don't know how fedora plays with Win 10, but I think it is also pretty easy.
If you want easy install the big distros are probably your best bet. A live usb might help you with fix/recovery as well, including looking at the partitions and seeing what's going on (fedora's install has pretty straightforward tools for this.)