LFFC
Ref your question on the second lump sum in case of death before the age of 65:
JSP 764 Part 1, 0411 (Death after leaving Service - Deferred Member):
"If a deferred member dies, his deferred pension lump sum will be paid to his nominated recipient(s), his spouse, civil partner or eligible partner or, if he has no dependants, to his estate. This lump sum will be adjusted to take account of inflation between his discharge and his death and the resulting lump sum will be tax free."
I take this to mean that, where there is a nominated recipient, spouse, civil partner or eligible partner to receive the payment, then the payment is made ouutside of the member's estate and is therefore not subject to any potential Inheritance Tax liability on the estate. consult an expert for confirmation.
Regards
Ginseng