Hold on to your seats…I have a good one.

As always – all assistance is appreciated

FACTS
T-IRA owner, 79, died in 2012
surviving spouse 100% sole primary beneficiary
spouse disclaims
Testamentary trust 100% contingent beneficiary inherits – via disclaimer
Spouse,78 is also the sole beneficiary of the trust

Note- I am not sure if the trust qualified as a look-through – lets assume it did

QUESTIONS
Whose life-expectancy is used? I would think the surviving spouse
Which RMD table is used? Single-life? The spouse has now inherited via the trust as a beneficiary Further – the “reduce-by-one” method is used” each year to calculate the RMD. Am I correct?
The kids – inherit upon mom’s passing. They can continue the stretch – they will be stuck using mom’s remaining life expectancy. Correct?

Bonus question – What could possibly serve as a reason for disclaiming – to inherit via a trust? It seems (to me) the client would be must better offer inheriting directly. no?