I only pulled one leaf out of my pack, I believe it was the second one from the bottom. That one alone made the front end come down about a half an inch or so and it also flattened out the pack a touch too. They're not level, but they are definitely not as arched as they were from new.
Add two leaves to the rear packs, firms up a squishy soggy ride out back, remove the one in the front, softens it up a tad, not so harsh and the truck pretty well sits level, maybe just a touch lower in the front now, but you can hardly see it.
Yes, I bought Rough Country front leaves and rear blocks, with their extended brake line kit and raised steering all at once. Still running the blocks in the rear, no problems, it's not a race car so I don't worry too much about axle wrap, plus with the added leaves, it's firmed up more anyways. Never any problems with the blocks, been off road a lot and have towed quite a bit with it as well.
I would not pull any more than one leaf out of the front either.