1. The team's success was due to her efforts.
2. The team's success was because of her efforts.
3. The team's success was thanks to her efforts.
[Can we use all the expressions? Are they the same?]
4. I have to drop by the bank to make a savings deposit.
5. I have to drop in the bank to make a savings deposit.
6. I have to drop into the bank to make a savings deposit.
[Can we use 'by,' 'in', and 'into' interchangeably without changing the meaning?]
2 is far better than 1 -- "because" is clearly setting up a cause-and-result idea in sentence 2. The word "due" has a different meaning (http://www.dictionary.com/browse/due?s=t ) although you'll hear and read this phrasing quite a bit. It just doesn't have the same cause-and-result meaning that "because" does.
3 is OK, yes.
I'd use 4 and 6; I wouldn't use 5 unless "in" were followed by "at."posted by Writeacher