Wouldn't that pretty much remove much of the worlds oil because of the radioactive fallout?
No.
No; it would only remove Arab oil. Producers in Venezuela and Russia will be forced to demand any price they want. I'm sure they'd hate that :-)
Q: How long did Hiroshima have to be abandoned before it was once again inhabitable?
A: Trick question. Hiroshima was NEVER abandoned at any point following the atomic bombing, because it was NEVER uninhabitable.