But the 500/1000 posts thing: it doesnt automatically load 1000 posts, you have to actively choose for it to do that, so if people are having problems with something they have chose to do, just let them know that is why they have a problem, and they can change it back? Or suck it up because they made that decision.
Anyway, I've not noticed a particularly long loading time with long threads, when mn is buggered its buggered, no matter how long the thread?
I reckons you just don't want it to be as "easy" as it is for people to read deleted threads after they go poof! 