Are you unable to amend the application form after you have paid the fee e.g. to change the intended date of arrival in the UK? If that's the case it seems like the best thing to do would be to delay submitting the application until all documents were in place and then pay for priority consideration to minimise the risk of something going wrong with the intended arrival date.
Yes, once the application form has been submitted, nothing can be changed on it. However, if you have put the wrong intended travel date, you can always make a note of the date you would prefer in a cover letter and hope that they honour it.
Having said that, the intended arrival date is just your requested date, and there is no guarantee you will actually be able to travel on that date - so what you want to do is put the EARLIEST possible date you are able to, or may wish to, travel to the UK.
- If the visa is granted before the date you put, the visa vignette will be made valid starting 7 days before the intended travel date.
- If the date passes before the visa has been issued, the visa vignette will instead be made valid starting 7 days after the decision has been made (to give enough time for you to receive it).
For example, you apply at the end of March and put a travel date of 15th June. Your visa is granted in April, but is not valid until 8th June... so you cannot travel until 8th June. However, if you apply at the end of March and put a travel date of 15th April, but your visa is not granted until 25th April, it will be made valid starting on 2nd May so you can travel from 2nd May.
Another couple of questions if I may. I work for a govenment department. One of the questions we need to answer in visa application form is the name, telephone number, postal address, and email address of my employer. Should I give the address of the pay and pensions department (who will be confirming my salary and length of employment etc) or the office address in which I am physically located? The other possibility would be the address of the HR department.
I would give the official head office address of your government department. I also work for a government department - our headquarters is located 250 miles from where I live and work, but if I was entering my work details, I would put the official address, phone number and email address of headquarters, not where I actually work.
UKVI should not contact your employer directly anyway - if they need more information they will contact the visa applicant by email and request that they provide further documents from the employer (basically they get you and your spouse to do all the legwork for them).
I imagine they only ask for your employer details in order to confirm that it is a legitimate company/department.
Secondly, I was formerly married, now divorced. As well as being a British citizen, I think my ex-wife also had Irish citizenship, but I am not sure. In the form we have to state if she has any other nationalities. We are no longer in contact, although I could call her if necessary to obtain the answer. Should I do that, or just say at the end of the form that it is possible she is a dual national?
If it's asking for other nationalities, I think the best thing to do would be to contact her to find out for sure, so that you can put a definite answer on the form, rather than just guessing or omitting the information.