I believe this is a bug in OS X 10.7. I also have a retina MacBook Pro. Mine is 2.6/16/512, and I noticed that there were 0 page outs but a very large swap file being created (mine was about 8 GB). Closing applications actively reduced the swap space being used. Again there were no page outs being recorded.
I believe this has to do with the sleep image file that also gets housed alongside the virtual memory files in /private/var/vm. When pmset hibernatemode is set to 3 (default for laptops, suspend to RAM and disk), sleepimage gets written upon sleep. This is why it takes a few moments for these laptops to go to sleep: it's writing up to 16 GB of RAM to the sleepimage.
However, changing this setting so that the RAM gets powered on sleep and NO sleepimage is written has resulted in no abnormal increases in swap file size. My suspicion is that the sleepimage is in some cases being preserved post-sleep and prompting the creation of swap files. Perhaps it is this incorrect behavior that is also resulting in the unusually large swap file sizes you are seeing.
From the manpage for pmset, to change to NO suspend to disk you would run in a Terminal:
sudo pmset -a hibernatemode 0
To delete the sleepimage (and reclaim 16 GB on your computer with 16 GB of RAM), run:
sudo rm /var/vm/sleepimage
I restart after these operations just to ensure there's no weirdness. On each power source, you can check the status with:
pmset -g
You should be aware that, in the event of a total power loss (battery dies and not plugged in) the contents of the RAM will not have been saved to the hard drive, and you will lose your work. For me, this is a small but calculated risk because the speed of sleep/wake, coupled with the great battery life and reclaimed storage space. Additionally, for me it seems to have mitigated this issue, which I have not seen on any other Mac laptop I've owned. I wish we had those battery indicator lights, though.
You seem to misunderstand virtual memory. Virtual memory is simply a mechanism that the OS uses to make it look like each program has its own, extremely large (4GB on 32-bit, 16 EB on 64-bit) address space. It also provides a way for the OS to use paging, all while making it look like (to applications) only real RAM is being used. In short, it's only an abstraction, and the "Virtual Memory" stats in Activity Monitor are meaningless (for 99% of use cases). You should not be worried at all about whatever number appears there, because it has nothing to do with whether "real" RAM is being used or not.
About your paging stats : you gave no details on how you use your system, so it's hard to know whether something's wrong or not, but I wouldn't be alarmed by a value of 7 GB. Also note that the reported values are Page ins/outs since boot, so if you keep your laptop on all the time like me, it's no wonder that the number accumulates after a while.
Best Answer
This is one of the all-too-few times where the answer is officially documented by Apple.
The short answer is that the system tries to keep a certain amount of memory free so it can quickly provide memory to an application when the application requests it. When there is not enough free memory, then memory that has not been "touched" in a while gets swapped out. Often this is memory that the application "leaked", which is to say allocated, used for a while (maybe just once), and will never use again, but forgot to tell the OS it was done with.
In Yosemite and other versions of OS X, SystemUIServer was notorious for leaking lots of memory. This would be a prime candidate for getting swapped out, because it was not needed by the app, but could not be reclaimed by the OS. Swapping this memory out to disk is all upside for performance; the only downside is a relatively tiny amount of disk space used.