Married to a student visa holder from Congo, have 6 kids who were born here in the UK

I did provided all the documents, and replied within 4 days, and even my DL for 3 years was issued before the 10th day deadline.
Remember, my 1 year DL has expired when they replied, but I met the deadline of 10 days to provide the information they asked for.
Now, I will compete 6 years in Early in 2016. (Don't be confused about, 1 year, and 1 year, and 3 years DL as it does not add up to 6 years, but the fact is, the delayed over 9 months before they issued the last 1 year, and some 3 months during the last DL visa. But from the first date of the DL in 2010, will be 6 years in March 2016.
Hence, I have the following questions;
1. Will they rely on me having a gap for 4 days, during the time they wrote to me to send additional document and complete a new form?
2. I can see most people saying, 2x 3 years, will it matter if I was given a mixed of 1 year and 3 years?
3. Can I be able to apply for ILR immediately I clock 6 years.