Floors can be co-ed “by floor” (as you defined it) or “by hall.” It just depends on how things fall. All bathrooms are single sex.
Bikes can be secured to racks that are located outside of each residence hall. Some also have bike rooms inside.
If there is a ‘roommate-conflict,’ your RA will be willing and able to talk through this with you. The RA will help make a decision on the best way to resolve the situation; rarely does it end in a room change, but it happens.