Yes, it's cetainly possible... Hard, but possible. However, you can't catch every Pokeman in one game. You would need to have multiple games, and bring each Pokemon into one game through trading and what not.
to catch zapdos in pokemon black you have to have every legendary pokemon
No not every pokemon. You can't catch the starter Pokemon and many of the rare pokemon, you have to trade with Diamond. sorry ...
No the catch rate is the same in every game
yes you can catch every Pokemon ever made
To finish the sinnoh dex (Pokemon platinum's,diamond, and pearl dex) you just need to see every Pokemon not catch every Pokemon.
trade a lot
depending on where you go and what you do you can catch all of them, every Pokemon in existence
battle trainers or catch the Pokemon
Yes. You can catch every single pokemon in the games.
No to get Cyndaquil you must catch all Pokemon from that region, because if you have to catch every single Pokemon, won't you already have Cyndaquil?
you cant
You don't need to catch every Pokemon to complete your pokedex you need to just see them but you can catch all of them if you want to.