No. There is only one Sudowoodo in the entire game...
easy stroomish
No, there isn't. The legendary Pokemon for emerald is raquaza and that's it. when you finish the Pokemon league, you finish the game.
In the Lilycove Lottery.
Dewford Town
Dewford Town.
A collector at the cafe near celcetic town has one if you want to see one
All contests are held at lilycove city.
it is found at the second floor second room of meteor falls
No. There are several differences. I'll only explain 2 of them. First of all, in Pokemon Emerald you get the abilty to clone Pokemon. The second difference is that Pokemon Emerald have both Pokemon exclusives in Ruby and Sapphire such as having both Kyogre and Groudon.
in the city after you get of the boat the second time
The starter Pokemon for Emerald are Torchic, Mudkip, and Treecko. Their second stages are Combusken, Marshtomp, and Grovyle. Their final evolutions are Blaziken, Swampert, and Sceptile.
You can't (unless you use cheats).