Question about process - from student visa to COA to spousal visa

Hello, and thanks in advance!  Members here were very helpful when I first asked about the marriage options and I hope someone can tell me now if I am missing anything glaring!

I'm a US citizen living in Northern Ireland on a student visa (expires end of January 2011, when I should finish my PhD).

I am engaged to and having a child with a UK citizen; we have been together for two years.  We have just set a date with the church here - January 8th, 2011.  Our plan is to have a later (April) reception/party in the US, as my family will not be able to attend our small UK ceremony.

We intend to apply for the COA in early October 2010; at that point I will still have the required three months left on my student visa, and it seems like that would allow us to (fingers crossed!) marry here on January 8th as we are planning.

Then - I understand that I can immediately apply for the spousal visa, without leaving the UK.  But obviously it will take more than 3 weeks for the spousal visa to be granted/processed - so between the expiry of my student visa/COA and the granting of the spousal visa - what would my status be?  would I be illegal? 

(While waiting on the COA to be given, I assume they'd have my passport, so I would possibly not be able to travel to the US to see family until that was returned. Correct?  And again after the marriage, they'd have the passports, so our planned trip to/reception in the States at Easter might be impossible?  I thought I saw a reference to a same-day spousal visa - is that possible?)

Sorry if these are 'stupid questions' or if I missed the answers in another post.  And thanks for your help.

Your status continues to be what it was at the time that you applied as long as you put in your application before the expiry date. It is possible to get your FLR(M) in person at a PEO, but it costs £200 more than the postal application. It's not quite same day though, as you won't receive your biometric ID card for a week to ten days.

Have you been living together for 2 years as of today? If so you possibly could qualify for FLR(M) already as the Unmarried Partner of a British Citizen.

Is the Church you're going to get married in a CoE? If yes the you don't need the COA.

If not, then yes you apply for the COA (which takes a bit of time from what I've gleaned from those who have done it), receive your COA, give notice, get married and then post off your FLR(M) application.

As long as you post off your FLR(M) before your current visa expires your current stay will be extended until the decision is made on your new application. You will be entirely legal.

Yes, they will have your passport to do your COA and your FLR(M) so you cannot travel during that time. You can do an in-person application for an extra £200 and it will be processed same day. However, you still cannot travel until you receive your Biometric ID card about 10 days later.

The other option is if your partner is an Irish Passport holder then after you're married you can apply under the EEA Rules which is free of charge.

Lots of things to consider.

Thanks, DrSuper and WebyJ!  That is very reassuring...

We don't live together currently, and he's not eligible for an Irish passport, so those options are out, I'm afraid.
We're getting married in a Roman Catholic Church; looks like we still need the COA. 

We also need (per Northern Irish requirements) to "give notice of marriage" - a minimum of two weeks and "up to" 10 weeks before a schedule (license) of marriage will be issued by the Registrar here.  Aaargh!  Our "notice" must be accompanied by the COA and passports. 

So now I am REALLY at a loss about when to apply for the COA!  This all means (as far as I can tell) that we must have the COA in hand 2-10 weeks before the wedding...but the COA expires 12 weeks after it is issued...so we can't get it too SOON or it will be expired by the time we are scheduled to get married!  How does anyone know when to apply???