Its called the vs seeker and you get by going in the vermillion city Pokemon center and speaking to the girl near the nurse.
no.
pikapoo
you battle with it or put exp. share and battle with a different Pokemon
The safari zone.
you cant
you can not, you can get a Pokemon that knows dive in battle but you cant use it outside of battle.
you receive the Pokemon searcher after beating the elite 4 and champion then go to sandgem town talk to dawn/lucas and she/he will give you the Pokemon searcher
Dive is not an HM in leafgreen you can't get it unless you trade a Pokemon that knows Dive from ruby or sapphire or emerald but it will not work in leafgreen unless your in battle.
No. Growlithe is a Pokemon exclusive to Pokemon FireRed Version.
all you have to do is battle people
defeat it in battle
you battle it by battling your cousin[name may very] if you get chazard in beginning.