OS X swapping with free memory available?
This looks 100% normal, fine and not at all even beginning to look like a problem.

Swap is for items that the system determines aren’t needed actively and frees up RAM for other tasks that can benefit. You have a very large proportion of free memory so the system is well in the green.

Apple’s activity monitor now has a “pressure” gauge so I would look at that and only worry if you see large page in / delays or yellow / red pressure on Apple’s graph.

To check page rates to and from swap, open a shell in terminal.app and run:

vm_stat 60


You will see counts per minute and the swap in and out are the ones to worry about. Next would be that you have a stable and low amount of free pages so that number going down to 0 or 10 would be worrisome about swap or allocations. Until then, you’re likely at full speed with any amount of swap that’s not filling your drive causing other issues.