I don't know what they can find out, probably all they want to providing they're willing to spend the resources to get it.
Why would you want to spend your career wondering what skeletons are waiting to manifest themselves. The aviation community is relatively small...
Own whatever you own. If you called in sick a ton due to bad luck and forces beyond your control, own it and explain about it. Called in sick a ton to go skiing, own it too but realize you reap what you sow.