You can always ask your previous attorney for a Letter of Release that states he/she will not be holding a lien on the case. This usually will get other attorneys to take a second look at your case. If you are able to contact an attorney for a consultation, be sure to speak realistically about your expectations of both representation and settlement. Your local Bar Association might have a referral service that could give you the contact information for some more attorneys to speak with.
Since this is his first offense, he would most likely be offered a deferred contract which states that he promises to complete a certain number of classes, community service and have no further contact with the move theatre for 6 months (maybe a letter of apology to the store manager) and if he successfully fulfills the terms, then his case will get dismissed. You should consult with a Juvenile Defense Attorney in your area.
A person in Texas has two years from the date of incident to file a lawsuit for personal injuries but once a lawsuit is filed, there is no timeframe for when the case has to end. If you are unhappy with the length of time it is taking to end your case, then I suggest setting up a meeting with your attorney to discuss the issues that are taking up time.
Not to sure how you can track him down after the fact without any identifying information on the actual driver, instead of just what type of car is it. You should call the cops and make a report then contact the Texas Crime Victim's Compensation fund to see if you would qualify for any medical bill reimbursement. You should also contact a local Personal Injury Attorney and schedule a consultation to talk about your case in greater detail.
I'm not sure what your attorney meant by saying you could "destroy" your juvenile record. There is a sealing and expungement process you could be eligible for since there was "no probable cause" stated by the prosecutor. I would have a discussion with your attorney about what your options are when it comes to either sealing your juvenile record or expunging it.
Sealing your records seals them from the public, but government agencies can still see them. As to whether or not you will be able to get a CHL, it depends on how DPS evaluates your CHL application. Be honest and forthcoming on your CHL application.