Tier 2 to ILR old IELTS and 5 yrs calculation

[anilavempati]

I had my Tier 2 granted on the 27th May 2013, but was unable to travel (from Australia) as I was on my notice period on my previous job and arrived on the 1st July 2013 (joined job immediately). I have applied with IELTS certificate (issued on 25th Aug 2011) in Genaral Training for my english language proficiency (written initially for Australia visa from India) with scores of
Listening - 8.5
Reading - 8.5
Writing - 7.5
Speaking - 7
With an overall band score of 8.
I have a couple of questions in related to my scenario above
1) from when I am eligible to apply for my ILR?
2) will my IELTS certificate still be valid to prove my english proficiency for ILR as I have used it when I applied for my Tier2?

Thanks,
Anila