Which of the following examples of speech would be restricted? using an obscenity in a film on political issues shouting "fire" in a crowed theater stating that your religious values have impelled you to take a particular political potion going door to door urging strangers to join your religious group

The best choice for that example would be that yelling "Fire" in a crowded theater would be restricted. The supreme court has ruled that in a situation like that, where it could cause panic and/or loss of life because of it, that type of speech would not be protected under the first amendment.

uhh idk for sure but i think it makes it difficult to pump the oil through the oil rigs

the density would be a smaller number.