I've heard that I can just do FBI to get something faster since FOIA takes up to a year to receive feedback. Should I only do one or both?
It is possible to do FOIAs to the border offices, ICE or CBP, and/or the courts that fortunately are much faster than the USCIS FOIAs. I usually have responses within 6 to 8 weeks, although it does depend on the office and information being requested. Since the FBI records often are incomplete and occasionally even incorrect, I certainly would not advise relying on the FBI background check alone.
There are three possible border stations, and I am not sure on which one the incident tool place. In such case I would have to do USCIS FOIAs. I'm very worried that there will be a deadline or quota to apply for Deferred Action. In you experience, how long do you think it will take if I get FOIAs from USCIS? Is there a way to speed up the request?
Actually, if you're not sure of which border point, you could try all of them. You also could try doing a FOIA to ICE in Washington, D.C. to see if they have the information you need. There are ways to expedite USCIS FOIAs, but that usually requires being in court proceedings. I'd recommend starting with ICE in D.C.