Would it be okay to take expired omega-3?

I wouldn't. It is never good to take or use expired medications or otc's. That is why there is an expiration date! why take a chance? Don't do it! they are cheap, so don't you be cheap! buy a new bottle.
Yes. Expired medicines won't hurt you - they just lose their potency. Most drugs are still okay for a year or two after the expiration date as a general rule.