Clergy as employees are not allowed to bring federal discrimination claims against their churches for pretty obvious reasons. Churches are also given some latitude in their hiring practices for other more essential employees (anyone in a ministerial role - also for obvious reasons.) They are also protected from any hiring decisions based on religious belief (For instance, a mosque is allowed to turn away Christian applicants for its custodial positions or require them to sign a faith waiver - this one is less obvious as to why since we’re largely in a Christian culture and don’t get it like other cultures, but it serves to protect places that are sacred sites. For instance, non-Mormons ain’t allowed in their temples and forcing them to hire a non-Mormon janitor to clean their temple is a buggery thing to do.) They are not though protected from gender or race discrimination for non-ministerial hires. So if a black Mormon wants to clean the temple, then the church can’t say No (although it gets tricky because if you are a true-believer, but think that say women shouldn’t be cleaning men’s areas, then would you even apply for the job if you were a woman? Is it de facto discrimination? I don’t know, glad I’m not a judge.)
As for sexual harassment claims-- Yes, a church certainly can be sued for sexual harassment and it does happen from time to time. Clergy are not immune from sexual harassment lawsuits. I would wager that due to the confidential nature of their jobs they get some latitude similar to a counselor or psychiatrist. So while 'Tell me what your sex life is like." is probably grounds for dismissal if you’re a manager at McDonald’s, it may not be if you’re a pastor counseling a married couple.
The real issue though if you want to sue your priest is simply statute of limitations. Sexual harassment claims typically have a statute of limitations of about a year depending upon jurisdiction. Sexual assault limitations are much longer in general and are a more ripe avenue for litigation. The reality is that there are fewer and fewer of these cases every year and most of the problems were from decades ago. The Pennsylvania report for instance basically dries up (though not completely) after 2002 when changes were made by the diocese and we’re well after statute of limitations for those cases.