Rare. Virdian Forest and Power Plant.
Yes you can trade leafgreen version Pokemon to another leafgreen version.
Pikachu can be caught at either the Viridian Forest, or the Power Plant.
You can't get pikachu in Pokemon colosseum you can see it but that's all, if you want pikachu you would have to trade one from firered, leafgreen, ruby, sapphire or emerald.
No, you can't get Pikachu as your first Pokemon on Pokemon Pearl or Pokemon Diamond.
NO!
Raichu never evolves. Unless you meant Pikachu, which evolves into Raichu. Or Pichu, who isn't in Leafgreen but evolves into Pikachu, then Raichu.
In Pokemon Yellow, the only obtainable Pikachu is the one you receive from Professor Oak. You have to cheat or trade to obtain another Pikachu.
Caterpie, Weedle, Metapod, Kakuna, Pikachu.
there are 5 legendary Pokemon in leafgreen version
LeafGreen version does not have Growlithe.
firered and leafgreen version
its only available in Pokemon leafgreen version sorry