UK ILR Application basic queries-NUI

Hi,

I hold a Tier 2 General visa and complete 5 years on 20 Nov 2019 if the criteria of 5 years completion is from the date when we first arrived in the UK or 31Oct 2019 if completion criteria is assessed when visa was first issued and not entirely sure what qualifies me. I was hoping with the help of this forum I should be able to get some help and would much obliged for any input on the following queries.

1. Immigration history question in the application form which I am quoting: Quote"When did you first enter the UK? It is the date when one is entered the UK when the period of stay we are basing this application started".Unquote. This is one of the input in the ILR application. Is this the date when we first arrived in the UK after obtaining Tier 2 General visa or it is a date when visa was issued? In my case there is a gap of 3 weeks between the date when visa was issued and the arrival date so not sure completion of 5 years would be based on which cut off date.
2. If application for the ILR is made online, how the appointment date is confirmed and all the documents are submitted.
3. What is the tentative lead time for getting an appointment for the fast track from the date when online application is submitted? Also the criteria of completing 5 years is it assessed on the date when appointment is made or when online application is submitted?
4. When is the payment of the ILR fee under fast track paid? Is it paid at the time of completing the online application or on the date of appointment?
5. Last for the employer reference letter and the leave of absence who is this issued to? My employer may require specific addressee details.

It is the visa issue date.

1. It is the date you entered the UK
2. After you submit your application, you will be asked to create an account with UKVCAS and book your appointments. All docs are ONLY scanned and uploaded and no original doc is taken from you
3. It all depends on availability. The date of eligibility is based on the date of online submission but as long as you are eligble on the date of decion, you are fine
4. You must pay before online submission
5. It can be addressed to the UKVI

Many thanks Zimba for a swift and to the point reply. On the last question is there a complete address?

Also two more question I forgot to ask. The first is if there is any minimum account balance requirement in the bank which you are aware of since I understand that we have to submit the bank statement (not sure how many months) and the immigration would like to check the closing balance and perhaps any extraordinary activities? Secondly since last 5 years I stayed outside UK in aggregate of only 15 days. Do I need any leave of absence letter from employer?

You do NOT need their full address. If necessary, find their address on internet.
You simply need to submit the last statement showing the money in your account matching the last payslip.
You can get a the letter it is up to you