you advise that for all marriages, anywhere in the world. I'd advise Thai brides to make sure that the wills are sorted out to stop money grubbing siblings of their husband leaving them destitute. I have known that.
Use an agent to.the running around. Once you have done the UK affirmation ceremony, it's pretty tight to get every translated, notarised and delivered to the MFA before 3pm when they close. 3 working days for them to rubber stamp provided they are happy with how your name is translated. Legally, in the UK, you do not need a translation. Agency will.charge about 4000 for a legal translated copy. I used Visa for You, chatchai penanarm to sort it out, and a UK visa for my wife who has a problematic passport history.
I lived in Belfast for years. Gard never stopped me for papers in a UK car, I was stopped by the police more often up north. Even when the border was armed, and during FMV, I could cross the border freely. If you flew into Belfast and drove south in a rental car, no one is going to stop you. Get a ferry from England or scotland to Larne or Belfast, you dont need a passport. Some, not all, Airlines and Ferries going directly into the Republic might set a passport requirement, but that's not an Irish government requirement. The Foreign Office advice is you should mot must have a passport. If you don't have a passport, you can obtain a Confirmation of British Nationality Certificate from HMG Incidentally, Thailand is included in the Short Stay Waiver Scheme, so some with a UK visitor can visit Ireland for a short time with needing an Irish visa.
uk to Ireland. It's a common travel area for uk and Irish citizens. A variety of documents besides a passport suffice for Americans/Canadians using their land border. Americans don't need a passport to go on holiday in Mexico.