While the three year statute of limitations apply, I worry that if you did not seek medical attention in the past year and a half that it will be difficult to prove that the accident caused your injury. Although not impossible, the longer you wait the more difficult it will be to prove causation.
Be patient with your attorney. Sadly attoneys tend to work much faster than insurance companies. Although I am a believer that the squeaky wheel gets the oil. Unfortunately you may be underinsured, but you need to keep track of your lost wages for the final disposition of your case.
I would prefer a specialist to a chiropractor in any case. The insurance company is going to have doctors with much higher degrees than chiropractors are going against you so it is wise to level the playing field. If you expect the best out of your resolution you need the best medical support. However, specialists are more expensive so be sure not to spend all your insurance proceeds on doctors. Each case is different, you need to talk to an attorney.
Your best option would be a misdemeanor compromise. Dismissals are important. You will have to pay restitution to the store owner and they need to agree, but it is the best resolution in cases where misdemeanor is possible.
Hire an attorney or pay the bond. But if your attorney files a motion to quash the bench warrant or if he/she can get the prosecutor to agree to getting rid of the warrant that would be better/cheaper.