If I were you, I'd be very careful about your attorney at this point. If you retained him in Sept. and he didn't do anything until December because you threatened to fire him, it sounds to me like he's not going to really concentrate on your case. You should really try to find someone else. You should have an attorney you can rely to get the work done, especially since you're not in the same state.
I'll be honest with you, you should prepare yourself that you won't get your son for the holidays. That's going to be your punishment for trying to get custody of your son.
A word of advise on the travel.....I know that you're trying to be nice by offering to pay for travel, but that's not going to diffuse her anger or make her act more rational. She sounds like she has the potential to be really vindictive (actually she's already proven that). Your always playing Mr. Nice is going to get old for you and she will try to use it to get over you (trust me, I've been there). As far as travel, I think you should offer to pay half, because that's fair enough. If you get custody you paying everything, not getting child support from her and paying HER child support will get really costly soon. Remember, when the child is with you, you will have more expenses. Also, all this money you'll be laying out will not make her any nicer.
You should file for an temporary custody since the child is not living with the mother. You are the child's father and have more rights to have your son than her mother. Have your attorney file for an emergency hearing. Also, is paternity established? In NY when my DD was born the hospital had me fill out an Acknowledgment of Paternity and therefore the courts didn't have to establish paternity. Having your name on the child's birth certificate does not establish paternity. If you do not have a form like that, then you also need to have the courts establish paternity before you can move with the rest.
Also, get ready for a fight. Read a couple of parenting plans that this site has. It gives you a good idea of fair and detailed agreements. You want to make sure it's detailed to avoid problems in the future. I had a home evaluation, the court ordered it for both parents. It was actually CPS in each state that preformed them in both homes (I live in NY, ex moved to TX).
Good luck and keep coming back here for advise and support. It has been a life saver for me!