I am considering installing suhosin on my web server in order to disable the eval function. Before i go to the effort, does wordpress use this function? I know there may be some plugins that use it and ill deal with that separately. For now i want to be sure that the core of wordpress does not use this function and will not crash code if i disable it.
No, not anymore.
A system like WordPress does not need to evaluate arbitrary code in core. For security reasons as well as a matter of best practices.
If a plugin needs it for something, it's doing it wrong.