Time and Requirement for ILR application

[jjs456]

Dear forum members - in particular senior members,
I got extension of my Tier 1 Entrepreneur visa on 17/11/16 for 2 years. I came to UK as T1 E on 21/09/2012 and initial T1E visa was till 05/01/2016. I applied for extension on 12/12/2015 but got refusal on 21/01/2016, submitted AR on 01/02/2016, again refused on 28/02/2016, reapplied on 04/03/2016 and visa approved on 17/11/2016.
My questions are
1) when I can apply for ILR - 5 years from 21/09/20012 or before end of current leave granted till 17/11/2018?
2) For ILR, is this correct that I do not need to submit documents for investment as I got my extension so it proves that I am allocated 20 points for investment, is this right? Can I withdraw my partial fund from business invested as DL?
3) when I apply for ILR, is there a single SET(o) from for both - main and dependent applicant? Do my dependent require any English language test certificate to submit apart from Life in UK test?

Many thanks in advance.
jjs456