The client currently by default installs as a service that runs in the background and uses all available CPU resources. It is set to run at the lowest priority, so any use you make of the computer will be done before the folding process. That is what they mean by using idle computer resource. You can adjust how much of your CPU is given to folding using the Configure portion of FAHControl, directions for using that are
here. You also use FAHControl to start or stop folding using the
Fold and
Pause buttons respectively. Deleting FAHControl will not stop the processing, and the background process will restart on its own if killed. The process can be set to not restart, but that requires FAHControl to do that without using the command line in Terminal.
Since you have already deleted parts of the F@H software, to get things back under control you should use the uninstaller. Hopefully it will be packaged with the installer in some future release. The OS X Uninstaller can be downloaded from the bottom of
this page.
I hope you decide to reinstall folding. Using the Configure function of FAHControl the CPU usage can be lessened. You did not mention the type of Mac you have, the default is to use a SMP setting of -1 which uses all cores/threads available. For example, on a quad-core i5 that would be 4. With a quad-core i7 that would be 8. You can set the number lower to 2, 3 or higher even number. You can also change the folding slot from SMP to be a uniprocessor slot, that will use only one core.
You can find additional information on folding with OS X in the
V7.2.9 OS X (Beta) forum. Or ask here. The (Beta) is because the client has some features needing to be brought up to parity with the Windows and Linux versions. Future releases are planned with easier initial setup and selectable performance levels instead of installing to use all available resources.