1). It's not "padding". It's a chamois. Cycling shorts have them for a reason. The reason is not to cushion your ass from the saddle. Once you find the right saddle for your butt, you won't need "padding". What you need is a chamois to help wick away the ball and ass sweat that causes what we know as "swamp ass" and which is what leads to saddle sores. All the padding in the world won't save you from a saddle that's an ass hatchet.
2). Anything that has seams is going to chafe the **** out of your ass and thighs on a long ride. Cycling shorts are seamless.
3). Anything made from cotton, or a cotton/poly bend, is going to stay soaked once it's soaked (with either sweat or rain). Trapped moisture in your nether regions leads to swamp ass, and for that, see 1).
4). Secure people don't give a rat's ass about what other people think, or snicker about behind their backs, or even to their faces. Get over the self consciousness of wearing proper cycling gear for long rides. Comfort trumps embarrassment in my book.