I believe the only available Hoenn Legendaries aside from trade, pal park, AR or events, are Kyogre/Groudon and Latios/Latias. Only Latios and Groudon are available in Soul Silver.
After you travel to Kanto you will eventually talk to someone who shows you a picture of Latios. it will then be a roaming Pokemon in Kanto, similar to the legendary dogs in Johto.
To get Groudon you must beat all 16 gyms as well as Red on Mt. Silver. After you beat Red go see Prof. Oak and he will give you a Kanto starter Pokemon and the Red Orb. Then go to Cianwood in Johto. Go through the cave leading to the Safari zone. When you come to the first cave with 2 ladders, go down. Surf west until you see a ledge you can rock climb. climb up and enter the cave where you will find Groudon.
Abra, Exeggcute, Machop.
The legendaries can be found in these locations: Mt Ember, Power Plant, Seafoam Islands, Cerulean Cave. The legendary dogs have no specific location since they roam around Kanto.
You can if you want to it's totally up to you i can say yes that's the best suggestion considering they overpower most regular Pokemon however if you want to prove yourself a true trainer you will not use any legendaries.
Most Pokemon will breed with ditto. You might need to catch another one because they probably don't like each other. Only legendaries and genderless Pokemon won't breed with ditto.
legendary shiny magicarp
there are 5 legendary Pokemon in leafgreen version
no but can in emerald!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
gameshark
In total including event only Pokemon there are 10.
A ditto with (any Pokemon you put in the day care accept for legendaries)
Abra, Exeggcute, Machop.
Moltres, zapados, and articuno are the three main legendaries in leaf green/fire red
Everything but preevolutions and legendaries.
The catchable legendaries are the following: Articuno, Zapdos, Moltres, Raikou/Suicune/Entei *depends on your starter pokemon*, Mewtwo.
Yes you can trade leafgreen version Pokemon to another leafgreen version.
use hacks:P:P:P
The legendaries can be found in these locations: Mt Ember, Power Plant, Seafoam Islands, Cerulean Cave. The legendary dogs have no specific location since they roam around Kanto.