Are your questions specific to the college program or general employment?
For the college program: You are hired into a role (ie, attractions, merchandise, food, etc); you accept that role and the company will place you based on what's available prior to your start date. You do not have any say on your final location, you can only control the role.
Housing - there are 4 housing options (1 is typically only for international students) and you will be able to voice a preference; but it comes down to what they have available when you check in. If you get married prior to your program, then you and your wife will be placed together in a single apartment.
For general employment: yes, you have control over where you'll be working. They'll tell you what they have available and sometimes you'll get a choice of a couple different places. No housing is available outside of the college program and specialty entertainment.