Use QWERTZ keyboard as a QWERTY

I want to buy a laptop with Windows 8 with the German keyboard QWERTZ but i will only use it for English and Greek language. So, i will change the language from control panel to English and work like this. I don't care if Z and Y letters will physically appear the opposite, or if some other strange symbols will be on the keys.

What i really care about and want to clear is :

If i switch to english/greek language using the German keyboard QWERTZ, will all the keys work exactly the same as in a QWERTY keyboard? All the letters/shortcuts/symbols/shift-ctrl-alt combinations etc will work the same?

Yes, the keys will work the same, provided the physical layout (i.e. number and placement of keys) is the same between your german QWERTZ and english/greek QWERTY keyboard.

For my localized danish keyboard, there is the same number and placement of keys, so I can use a US keyboard layout with no problems on my physical DK (danish) keyboard.

Yes, it is the same for the common keys. Take please a look at this Editorial: Moving from QWERTY to QWERTZ on short notice

Glance at the image of a German QWERTZ keyboard above, and the letters are all in the same place. The only obvious differences are the accented characters, and the location of Z and Y. Look more closely at it, and you'll notice something else that differs. The punctuation is radically different.

Yes - the key that is a "Y" in English keyboards and a "Z" in German ones is in both cases the one that sends the scan code 15, likewise for the Z/Y key being scan code 2E; the differences are, like most other keyboard layout differences made in software rather than by the hardware being different.

There are some physical differences, such as the extra "102nd" key (scancode 56, <> to the left of Y on the German keyboard shown above) not being present on US keyboards, the Enter key being shaped differently, and scancode 2B (US Backslash, German #) being in a different position, but in general if you select the keyboard layout you are used to touch-typing in you won't get any surprising results.

In general keyboards by the same manufacturer have the same internal circuits (with some provision for the scancode 2B key being in multiple places, if they make both US and European keyboards), with only the keycaps being different.

(The codes I've mentioned are "set 1" scan codes, as used in the scan code field in MS Windows WM_KEYDOWN etc messages. The actual codes sent by the keyboard are almost certainly different ones that are translated by the keyboard controller or operating system)