I was puzzled by the 7% figure too. The spending increased with assumed inflation, but it wasn't clear whether the 7% was a nominal or a real return. Please clarify.
Here in the UK, pension funds enjoy a substantial 'heritability' advantage over other 'wrappers' - they can be left to the grandchildren and untaxed in their hands until drawndown, and do not count towards their own capped pension funds. So many here think of their pension as the very LAST thing to touch. (It's called the location withdrawal problem by Sharpe).
They also think in permanent endowmnet terms. This means a) stick to real assets, b) spend no more than 3% to 3.5% of the moving average of the market value over twelve trailing quarters. This should leave the capital value at age 95 about where it was at age 65, and the grandchildren put your portrait over the mantelpiece...