Questions about Dungeon Farming

i have a few questions about making an account purely for the purpose of dungeon farming



1. What is the best way to bot level 1-90?



2. What is the best class/spec to dungeon farm?



3. Isnt there a limit to how many instances you can enter during a certain amount of time, like it says you have entered to many intstances blah blah.. do people bypass that some way or what?

Questions about Dungeon Farming