True, the option has been removed in later versions. But it is an easy fix to just hack the Info.plist in the bootcamp files (easy to do and easy to reset, I had never hacked a file before). Then u get the option to create an USB from an iso-file. Here is an easy
video to guide you thru the hack.
The other problem still remains but I think you can get around it if you use rEFI.
Download the latest rEFI, install it and reboot your mac twice. On the second reboot you enter rEFI without holding ALT (and will alwasy do that untill you uninstall it). From here you may choose what "disk" you want to boot from.
I hope this works for you!