Ungamer

haki doesn't negate the elemental effect. Kaido used his breath on luffy and it was pretty effective. Haki can only help you effect the df which normally wouldn't be possible like punching a logia or hurting a rubber body.

He has gold freely available and as it is Skypia I don't think he can get other metal in enough quantities.

oooohohohohoh!

Can't he use it as Spiderman's webshooter. I know that to use the web to swing yourself around you need better physical capabilities and senses which he got for speed based power so he can use it i guess.

I don't think so. They just had more time than Luffy so they are much stronger than him. Innate talent of Big Mom (tough skin) might feel great but only during initial stages. You can achieve this through Devil Fruit too and later on people with Better armament can easily injure her.

So cultivation progress is not to next stage (first stage to second stage) but rather total progress (entry stage to last level).

Aisa also had Mantra.