There aren't "ancient creepers" in the application version of Minecraft, there are creepers.
No, Creepers just flee from them.
Yes, creepers were an error, they messed up a pig...
Yes
No hostile mobs (including creepers) are present in peaceful difficulty.
Nothing.
Yes
They explode once they sees you.
Kill Creepers.
Yes, they will explode.
Yes
No, Creepers do not burn, the sun burns undead such as Zombies and Skeletons.