Windows
According to AnandTech:
Windows 7 by default starts up at 800 x 600 on the Retina MBP, Windows 8 defaults to 1024 x 768. This behavior isn't specific to this system, the GeForce GT 650M doesn't have native driver support in either OS at this point and these are the defaults for the standard VGA driver in both cases.
Windows 7 won't expose any resolutions higher than 1600 x 1200 without an actual NVIDIA driver, while Windows 8 will let you select the full 2880 x 1800 panel resolution.
This is a report about Windows via bootcamp. I don't know how this differs from Windows being used in a virtual machine. It would probably also depend on the options that the VM software offers.
Linux
When using the NVIDIA drivers on Linux (and on Windows too) you can select the full native panel resolution (2880x1800). You can also select any of a number of scaled resolutions which don't look as sharp. In general, running at native resolution is actually less of a problem for Linux than it is in Windows and OS X because of the way it's designed. There are no blurry fonts on 3rd party apps like on OS X and it is easier to set your DPI so that apps are scaled properly than on Windows (it is set automatically in Linux).
Alright, let's see what we can do here!
1) Suspending vs. Shutting Down in Parallels
a) How it affects the host OS
Both options do not affect the host operating system - in your case, OS X - from a resource usage standpoint. Rather, they only affect how the guest OS will boot next time - (i.e. waking up from sleep vs. a cold boot).
When suspending, it works just like a physical Windows machine: it saves the current state of the operating system for later use. Unlike a physical machine, however, it uses no extra battery power, RAM, or CPU cycles to do so; Parallels unloads it from RAM and stores it purely on the hard disk (think of it closer to a Windows laptop "hibernating" than "sleeping").
b) How it affects the guest OS
On the other hand, both of these options have a more prominent effect on the guest OS. Aside from the standard reasons one might want to shut down a computer versus letting it sleep (updates, troubleshooting, etc.), there's one other reason to shut down the virtual machine: Parallels locks down quite a few of the guest OS settings (boot order, coherence mode, shared apps, etc.) and prevents them from being changed if the virtual machine state is anything other than shut down.
c) Which should be used?
In my personal experience with Parallels, I have found no issues with using sleep consistently between sessions. The only time I shut down virtual machines is if I want to change some of the Parallels settings for that particular guest OS or if I encounter an odd bug that can pop up in Windows from time to time.
2) Resource Usage
a) RAM
A set amount of RAM is reserved specifically for the guest OS - which you indicated to be 2GB; Parallels will not use significantly more or less.
b) CPU
i) Usage
CPU, like the guest OS hard disk, is used on an "as-needed" basis and is accurately reported in the Activity Monitor.
ii) Reservation or parking
Parallels will not reserve (or "park") cores; the option you see in the guest OS options (Hardware > CPU & Memory > CPUs) merely limits the number cores that the guest OS will have access to rather than purely reserving them exclusively. This way the guest OS can extensively use these assigned cores, and if the guest OS begins to have a large work load, the host OS can use the remaining cores to continue its business without having processes choked from the guest OS.
Hopefully that helps you out! If you have any questions or need clarification on any of that, comment and let me know!
Best Answer
airmon-ngis a part of Aircrack-ng and if you want to use the Aircrack-ng software suite in a VM you'll need to provide your own USB Wi-Fi Network Adapter attached directly to the VM since Parallels, VMware Fusion and VirtualBox, only provide a wired Ethernet adapter to the VM.