I think with all situations it’s fair and even amicable to say that “I prefer not to sign documents without the guidance of an attorney.” It’s a little suspect that they are using bullying tactics to get you to sign. As others have indicated, your pay check is not a bargaining chip—you are legally owed that money. And you are correct, you should not take on any unnecessary liability.
Not only would I tell them that you aren’t going to sign until an attorney looks it over, I would suggest that you actually hire an attorney to have a look at it. You could even have your attorney call them and indicate that you aren’t going to sign the document until he/she has the opportunity to review it with you.
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