Could an employee have potential case against company, if employee feels he or she is in hostile work environment due to harassment and threats?

There is not a legal claim simply because the employee feels s/he are in a hostile environment.  Harassment, including hostile enviroment harassment, is unlawful only if it is directed to the victim due to race, color, sex, national origin, religion, disability or age 40 or older. If it is not directed for one of those reasons, then it is not unlawful no matter how bad the conduct may be.