You can bid for whatever you like (multiple 4 days off back to back), but you WILL NOT get it. Only the top percentile will ever get that.
And also you cannot bid for 15 days off. You can only bid for chunks of 7 days off at a time. But I know what you mean.
You don't really have much to decide about right now. You only have a decision to make once you have an offer. But being informed is always wise.