Firstly, the windows version appears unlicensed when I open it with virtualbox.
That'll always happen when you run Windows 8 in any VM if you've already used its product key.
A Win8 product key is only valid for registering one Windows on one computer. Win7 and Win8 create hashcodes based on your hardware configuration to associate that product key with that specific PC.
Major changes in a PC's hardware ? such as a boot drive, CPU, motherboard or graphics cards being upgraded - can cause the hashcode to change, making Windows think the product key is being used in two PCs.
A similar thing occurs when running Bootcamp-Windows in a VM. When you boot up the VM Windows detects a major "hardware" change, and asks for a new product key.
You can purchase new product keys from Microsoft, but they cost as much as Windows does. You could also try asking for a new product key by telling them you've upgraded your motherboard and CPU and need to reinstall Windows and the product key is no longer working, or you've simply lost it. Microsoft will ask for some kind of proof of purchase though. I don't know if this could get you two valid product keys - but I doubt it.
There was a register hack with Win7 that could workaround this issue, and there is one for certain versions of Win8. I haven't tried it. If you want to try this, Google will take you where you need to go.
I haven't installed XP using Bootcamp, as Mavericks only allows you to install Windows 7 or later. I do have Win8 installed using Bootcamp, and run it as a VM through Parallels. But I've been unable to get Virtualbox to use my Bootcamped Windows for a VM: I just don't have the IT and coding skills needed to follow the how-to guides.
And with XP I don't have to deal with product key issues, I can use Construct on my Mac OS 10.9 desktop, plus XP is faster than Win8: Virtualbox boots to XP in under 5 seconds.
I haven't encountered any problems with running Construct under XP (32-bit, service pack 3, Apple Bootcamp drivers).
he display adapter appears differently on the virtualbox (it uses its own), while on the bootcamp version the correct display adapter is used (from intel in my case).
It's vice-versa for me: Virtualbox/XP uses Bootcamp drivers from Apple, but Parallels/Bootcamp-Win8 uses Parallels' drivers, which causes Construct 2 to crash. It runs OK if I boot directly to Win8.
@AbidSyedK: Virtualbox is free, but I've found Parallels to be (comparatively) more user-friendly.
That doesn't mean Parallels is easy to use, but as it's aimed at domestic users, not IT managers, it's probably as easy as creating a virtual machine gets.
If you use Virtualbox you should also install the relevant Expansion Pack and Guest Addition CD image to get all of its functions working.
EDIT: I edited this post to make my description of the Windows Product Key issue clearer.