Well it doesn't mater what pokemon u havebut what level they have pokemon at lvl 70 or more have a greater chance because the elite four have pokemon from lvl 40 to lvl 60.
The Pokemon League
The elite four will be at the Pokemon league.
Celebrate.
Actually you cant. you must defeat the elite four first, unlike Pokemon emerald. you can go check about a Pokemon ruby warp hack by searching Google or bing.
You can battle your friend at any time you don't have to beat the elite four.
You can only catch it after beating the elite four however you can get it from a friend before defeating the elite four.
DANCE
you only have to beat the elite 4 on Pokemon fire red not ruby
beat the elite 4 and talk the guy in the one island Pokemon center and then head to mt ember and you will have to beat 2 rockets to get the ruby.
yes . raquazas location does not open itself until after you beat the Pokemon league
go to Pokemon elite 2000 on Google search
yes swarpert is a greatest Pokemon to defeat elite four