Yes, the lowest level Pokemon can be is level 1. There are, however, some Pokemon, such as legendary Pokemon, that are only found at a certain level, and cannot breed.
I am not too sure.
only low leveled magikarp
it all depends on the Pokeball, HP, level, and the Pokemon for example, normal Pokeball - Low chance on a high leveled pokemon, but good on a low leveled pokemon Greatball - Really good on low leveled pokemon, but pretty decent on high leveled ones Ultraball - GREAT on low levels, really good on high levels Masterball - 100% also, with the Generation IV new pokeballs, it depends on time, location, and times captured(Repeat Ball)
go to twinleaf town and go to the patch of grrass near it
you could but it can be tough. i think your Pokemon should be at least LV. 47. THIS GOES FOR GROUDON TOO!
In Snowpoint Temple. You need the 3 Regis to awaken him. Bring a low leveled pokemon, as he is only Lv1. I'm serious.
Depends on the level it started with. If it is low leveled it will level up more than if it is high leveled. If it is high leveled it might not level up at all.
You can find high leveled Pokemon at sky pillar and victory road.
In the Sliph Co. building one of the employees will give you Lapras (it is low-leveled, so you have to raise it).
make the low level pokemon be in the front so it will battle and then swap to a higher level'd pokemon ( if you let the lower level'd pokemon hold the exp. share, it will gain 3/4 of the experience )
Machokes can be found in the wild in Mt. Silver or other high-leveled area caves. You can also catch a Machop and train it. Machops can be found in various low-leveled caves, such as Mt. Mortar.
Have the Pokemon hold a lucky egg.