Hi Darkrev,
This Forum relates to DWP Benefits and unfortunately cannot advise on taxation.
As far as rules regarding " living together " or being in the same household there is case law on the subject both regarding DWP means tested Benefits and Council Tax ( for Single Occupier Discount ). I think once a couple marry the authorities will claim that you are " living together " and in the same household for Benefit purposes and it will be your responsibility to prove otherwise. The fact that you have separate addresses where you spend the majority of the time would not prevent this.
David
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
