What would be considered a dead ball?

[SanDiegoSteve]

PJUMP,

There is no one quick answer for your question. Sometimes interference is an immediate dead ball, and sometimes not. Same with obstruction, some immediate, some not. There are other dead ball situations, such as a HBP, foul, umpire calling "Time," etc.

You need to study the rule book in depth, and it will explain whether the ball is dead immediately or not.