Generally, you can fire your current attorney at any time. The process is pretty simple. Your new attorney will file a notice of substitution of attorney with the bankruptcy court and attach a fee agreement with it.
Be aware that you may go from a flat fee to an hourly rate when you switch bankruptcy attorneys in the middle of a case.
You should speak to a local attorney to see if they can assist you in moving your case forward.
I would not recommend changing attorney's once the case is filed based solely on your interaction with the paralegal. I would let the attorney know that you are having problems & explain exactly what these problems are so they can be addressed. No one is perfect and someone needs to complain when a staff member is rude and isn't doing their job!
If you feel you cannot continue to work with your current attorney, you can simply hire a new attorney and let him/her take care of the ugly details of telling your former attorney "you're fired."
Hope this perspective helps