Block smoothing filler over large surfaces

Thanks for the advice, everyone. Here's what I discovered I was doing wrong:

1. Too fine a grit. I thought 80 grit was enough to shape Rage Gold. It really isn't. I've ordered a roll of 36 grit to try this mess again.

2. Too small a block. My longest block is 16 inches. Not good enough. I went back and forth on the length of block I should get, and finally settled on a 27" block with removable rods to adapt flexibility. These two problems were leading to number 3 which was...

3. I'm pushing too hard. This needs a light touch, which I wasn't giving it because the grit was too fine and I was trying to cover a large area quickly.

Unfortunately, I think I've sanded too low to fix at this point, so I'm going to have to reskim the whole thing a third time. It's infuriating because this all started over two little high spot dings in the deck lid. I tried to hammer one down gently, which led to "oil-canning" which led to more hammering, which led to thin metal, which led to torch shrinking, which led to a dinner plate sized area of mess.

Skimming the whole thing still seems to be the best option since it's such an obvious part of the car, and I want to cover the other high spot (remember there were two dings) as much as possible. It's in almost the exact same spot on the other side of the trunk as the one that caused the oil-can nightmare, and I'd rather not repeat that.

Thanks again for all your help. Hopefully this will solve my problems and I can put this all to bed.