Yes, they can be very reliable if you get the right one. Some controllers get outdated because of game patches but most will be good. if you search the internet you will probably find many good ones. i got mine from gamersoption.com and it has worrked good. I would try giving them a look.
No.
Gaming Modz
Fryz electronics
No but they will result in a suspension from the Xbox Live Service most likely a per meant one.
I bought my controller from www.gamersoption.com and I love it. I think that they have the best controllers for shooting games like call of duty.
yes
No, original XBOX controllers do not work for the XBOX 360.
yes you do the run the iso files(games)you have to have a modded xbox 360 unless you use the same programs microsoft does
It is 4 controllers on every Xbox 360.
if by modded you mean a flashed then yes but evan if you are playing official xbox 360 games you can still get banned from xbox live
Yes, all xbox 360 controllers work on the xbox 360. (no matter what color it is)
Promodz has the best. Probubly the cheapest, but you can go all out and get some awsome custom controllers.