No, not exactly. If you mean the installer can only do a 'whole' disk then you are correct. But there's nothing stopping you from doing a custom install. It is very much possible to install both Windows and a ZFS FreeBSD on the same disk. I've done so in the past.ZFS can only be installed with 'entire disk mode', so you need to format your entire hard drive to use *only* ZFS
When I booted the Windows installer 'traditionally' I wasn't able to create GPT partitions, apparently it was only possible to create one when I UEFI booted the installer. Mind you this was on a completely empty disk, I don't now what happens if the GPT partitioning is already there.You can install 64-bit version of Windows 7 on a GPT partioned disk without UEFI.
I didn't know that. I tried using ZFS alongside other file systems before but with no success, and I did not found enough information on the internet, so I gave up. Thanks for the tip, maybe I try that in the futureNo, not exactly. If you mean the installer can only do a 'whole' disk then you are correct. But there's nothing stopping you from doing a custom install. It is very much possible to install both Windows and a ZFS FreeBSD on the same disk. I've done so in the past.