Yomont, Thanks for posting about the support order. I suspected that the only orders in your case was a support order and was probably administrative in nature ... no court appearances and a judge just signed a stack of papers. Likewise, there was not a custody determination by a court and visitation was left to agreement which has not worked. Is that correct ?.
The reason this is important is because the parties are in different states and the laws are different if both parties are located in the same area and there is a 6 month rule governing interstate custody proceedings. It is usually better for you if you can file in your state ... the intertate issues are not an issue unless they are contested. Of course, it is a detrement to you if legal filings are in Colorado which could cause you substantial missed work, travel costs, etc but the main issue is that fathers usually do not fair as well in out of state courts.
At this point If I were you in your circumstances I would function as follows (and I only post for your considerations) :
1) Continue to focus on child
2) all your speaking (attorneys, etc) should focus on childs lack of access to her father
3) try not to talk negatively about the mother (except attorneys, etc or on this site)
4) cut back on verbal communication attempting to obtain agreement for visitation this summer. Present a written agreement of what you want and demand a response by a certain date. Only you know if it needs to be on attorney letter head. Take "agreement" to your local court (competent to make custody decisions) for judge signature and file with court clerk. Send signed copy to mother (no advance notice to avoid turmoil). Provides some credibility to agreement and may greatly help your cause in the future. May wait to get child before you do this. Or filing ex-parte (temporary orders; without notice). Adequate attorney can advise.
5) consider keeping child longer than mother agrees...it would be understandable under the circumstances and there is no current
court order.
6) review information in the articles section of this site ... much info. presented and verified by experienced common folks over a long period of time
7) become comfortable interviewing and managing attorneys; hopefully those 100% behind the cause

anticipate an increase in CS if your income has increase substantially since initial support award. By the way, i admire your objectivity concerning CS. I was the same way.
9) be aware, with the mothers history of manipulation and and violence, lack of access to other parent...child may be in an abusive situation
10) IMHO, matters concerning reducing CS for transportation costs, etc are for final negotiations...you have bigger fish to fry at the present.
Remember these points are for your consideration . Other posters may want to add to or detract from these points.