happiness is not a displayed stat. in order to check it you must talk to the little girl in the town east of Maulvile city.
Happiness maxed
Yes, it will evolve through happiness.
It doesn't, sorry. You have to trade it from Pokemon Emerald, Pokemon Ruby, or Pokemon Sapphire. Togepi evolves via happiness and happiness didn't exist in LeafGreen.
It evolves by happiness
it evolves when it's happiness is highest
Igglybuff evolves in "Pokémon Sapphire" when it's at maximum happiness.
jeffrey need Pokemon
Maxing out the happiness of a pokemon is somewhat time consuming. Walking around with the pokemon in the lead position will help slowly increase the happiness. You can also feed the pokemon poffins to help raise stats and happiness.
Pokemon Ruby has Pokemon that Pokemon Sapphire does not and Pokemon Sapphire has Pokemon that Pokemon Ruby does not.
There is no Pokemon mansion in sapphire.
He is not in Pokemon: Sapphire. You will not be able to find him. He is in Pokemon: Diamond, Pokemon: Pearl, and Pokemon: Platinum. You will definitely have trouble finding him in Pokemon: Sapphire.
Evee is not availiable in Pokemon Sapphire.