That's a die break in the 'R' in LIBERTY. I think the 9 in the date is just flattened but it also resembles a die break. Also, just a guess but I think the reason your coin is so shiny is because it was heavily polished after it left the mint. Even mint state coins don't have that type of luster. Oh and cuds are basically just blobs of excess metal on the rim of a coin. They can happen on any denomination. Here's one I found on a nickel I got as change: https://www.cointalk.com/threads/my-first-cud.315141/.
I could be wrong but it does not take much, just a pin prick through the plating, to start the process of it pushing out under the right conditions. Heat, moisture, etc. I always stand to be corrected tho.
Very interesting coin that 1956...looks like the date and "LIBERTY" was replated or struck in aluminum. Doesn't look the same as the field, is it the way the photo was taken? Hope this is not like the "blue or gold" dress thing...and I'm seeing things differently than most.
Zinc doesn't melt until 415 C. Cotton would catch fire before that. A clothes dryer will not melt the zinc from a cent. I've melted them with a large Fresnel lens (flat magnifying glass) and sunlight. In fact, I've made zinc boil out of a cent, complete with puffs of vapor that turned to zinc-oxide smoke, although it needs to be just the right super-sunny day for that to happen.