Complicated timeline problem.

[us.student]

I am a citizen of the United States, and am a university student, set to graduate with a 4-year degree this December. I wish to apply for a fiance visa to marry my partner, who is a British citizen. She is disabled, and we plan to apply using her DLA benefits to exempt her from the annual income requirement, so that she can sponsor me. She currently receives 184 GBP per week in ESA and DLA combined, which we will count toward "adequate maintenance". She also receives a housing and council tax credit. I have several facts that I would like to share about our case just to give an idea of the potential complexity, as it might affect timeline:

1. I am 14 years divorced, and had a child at the time of my divorce. My ex-wife divorced me, and took custody of the child. I have not had contact with my ex-wife or child since then. The divorce decree shows court ordered child support amounts. I was never asked by my ex-wife to pay the child support, and she re-married only days after our divorce. I have since learned that my child was adopted by her new husband. (I've been advised by a few consultants / solicitors that this item shouldn't be an issue.)

2. I was charged with shoplifting in 2004. The charge was dismissed, with a fine. The item allegedly shoplifted was a bottle of water, worth less than $2. In Texas,
where I resided at the time, this is a class C misdemeanor, punishable by no more than a $500 fine. In 1999, I was charged with criminal trespassing. In this case, I entered an abandoned commercial building without permission. The charge was dismissed on condition of probation. In Texas, this is a class B misdemeanor, punishable by no more than a $2500 fine and/or 180 days of time served in jail. (These would seem to be spent, were they convictions. Though in fact, they aren't technically convictions.)

3. My English partner is pregnant with our baby, and will likely deliver around late February.

Given our situation, I have some complex (and fairly urgent) questions to ask about our case, concerning the timeline of my visa application and planning of our wedding.

Foolishly, I did not realize that I would not be able to travel to the UK as a visitor while my fiance visa application is being considered. We have made plans around two important events, and it will be very difficult to change any of it:

1. I've booked airfare and accomodations for myself and my family to visit and meet my fiance and her family from October 10th to 16th.

2. We have made plans / bookings for a wedding to take place on the 22nd of December.

3. Things are complicated by the fact of the pregnancy. My partner will be pretty far along in December, and we don't want to go later into the pregnancy for the wedding. We're afraid that if we wait until the baby is delivered, it will negatively impact our chances of being approved for either the fiance visa or the spousal visa to follow. (Since proving that we have adequate finances is already a concern, adding a baby to the picture can't help!)

If I traveled to the UK as a visitor during October, I obviously couldn't submit my fiance visa application until sometime after I returned, around October the 20th (the following Monday). I'm here to see what options we might have for making this work. Here are my queries:

1. Given the complexity of our case, could priority service still help? If we submitted the application by priority around October the 20th, how likely would we be to have a decision before the 22nd of December? In general, given our case, how long might we expect to wait if we go by priority?

2. Since priority is a "rushed" service, does it affect the outcome in any way? Are decisions likely to be less fair in any way?

3. For my own reference, what things are required to prove that we intend to be married after receiving the fiance visa? We were thinking that paying for church, license, venue, etc., would go in our favor. These are things we can point to on the application. But what is a person to do if they make plans like this and the visa doesn't arrive in time?

4. Is the fiance visa multi-entry up until the point of our marriage?

Thank you for any help that might be offered, this has been an impossibly stressful time for us.