ESA(CB)ended,clarification of NI Credit Final Pos?

As alluded to before the official cessation letter confirming the cessation of one years ESA(CB)has now been received.
The letter points out that people with either savings or working more than a certain number of hours each week(I think)cannot "usually"receive ESA(IR).
I was wondering firstly why it adds the word "usually"?Does this mean there are rare exceptions to this rule that you know of?
But my main point continues to concern The NI Credits final position.
HMRC sent an A4 summary letter a while ago listing all the years NI Credits had been paid in and as you have mentioned before,the correct number required per year( 52/53) ticked the boxes in 33 out of 36 of the years.
the letter began "you have 36 qualifying years to 2012"My first reaction was thats OK no more are needed.
But qualifying here appears to mean relevant/applicable rather than fully paid up.
3 of the years do not have enough which was due to unsettled work/benefit patterns at that time.
By each of these entries it reads "Too late to pay now"but also reads simultaneously
"Amount £ needed=zero".Apparently these "missing years"cannot be topped up now as they were in the 1970s/80s.
All this leaves me puzzled.Please,am I covered for a full state pension or not?
Have I 33 or 36 years?
This makes a big difference as to whether I decide to continue to try to claim NI Credits for another 3 years or not.
If I close the claim now will I lose those 3 years proportionally at Pension time or is the Pension its self jeopordised?
You said before the law may extend the credits needed to 35 at some time in the future?

Yes on further reflection and re reading the letter it does appear that I am those 3 years short,
with 2012-2013 under the belt that will only be 1 year short of 35.
This means it might be worth keeping the Claim NI Credits only until next April 2015
to obtain the full 35 years worth.
What, given current events ,would be your guess at what ATOS/DWP might do in such a case until then?
Would there be do you think a LCW assessment (or more than one)?
Is it correct to say that as I am no longer in receipt of ESA no further attempts to enroll in the Work programme would be received?
As I am no longer in receipt of ESA does that free me from a requirement to be available
for work attend JC+ placements or so on?