On previous Parallels installations including my wife's current Par5 installation, pressing the "alt" key and holding it brings up a option menu to further boot with either OS X or Windows. I just installed Par7 on my two computers (MBA and iMac). My iMac has been running with Bootcamp for about 2 years now (no Parallels). I just installed Par7 over Bootcamp and then imported my Bootcamp Windows to it. On my MBA, I first installed Par7 and THEN, Win7. Neither one of these computers offers the cold boot option to go directly to either OS X or Win7. Is this something that was left out of Par7? My wife's Mac Mini still shows this option when booting with the Alt key held down.
You installed Windows as a virtual machine in Parallels, if you want a boot camp installation you have to run bootcamp assistant and install Windows, only them open it on Parallels (it doesn't really matter if Parallels is installed or not to create a Bootcamp Windows installation, this is totally independent from Parallels, if this sound confusing then you need understand better what Parallels is as a program and what it does).
If you have imported your BootCamp at iMac to Parallels - means you have moved WIndows from Mac's hard drive to Parallels virtual machine. To check the difference between virtual machine and boot camp please read this kb http://kb.parallels.com/en/112440 and http://kb.parallels.com/en/112941