Re: In hindsight what changes would you do
Whether the 8 year retirement was originally planned or not, I'd like to see the proof that anything alternative was planned.
I really disagree with the whole "TDKR was Plan B" line of thought. I'm not saying it was Plan A, I'm just saying I don't think there was any detailed plan in place while Ledger was still alive. The original plans for the third film were scrapped when TDK was first written. They condensed Harvey's arc and let it play out entirely in TDK, giving it a closed ending. From there, the story could have gone anywhere. Nolan gave himself that freedom by making TDK a stand alone film.
Besides, let's say they made a third film without the 8 year gap. Still reasonable to assume the ending would be the same, no? Goyer and Nolan supposedly discussed what the last scene of the trilogy would be during the Begins brainstorms. So Nolan always wanted it to end with Bruce moving on with his life, I think that's inarguable. IMO, the ending would still piss people off cause you'd have Bruce retiring at a young age with a short overall career as Batman.
And if you argue that they could have had the 8 year gap with him still being Batman the whole time, but then him retiring at the end wouldn't work nearly as well because it'd be harder pill to swallow if it was the first time we saw him retiring. We'd question it and say that Bruce could never live without Batman. By showing how miserable he was without it in the beginning of TDKR, it gives him a real arc to go on so by the end when you see in at the cafe, you know he's finally at peace and he's done FOR GOOD now.
Bottom line, I think for the retirement ending, having him retired in the beginning was the best way to go. It establishes his "default mode" as retirement. He goes through his final journey as Batman and goes from a miserable forced retirement to actually being able to find the will to live beyond Batman and end things on his own terms. Seeing the "bad" retirement helps the payoff of the "good" retirement immensely.