Debutante my grandparents lived separately in the same house for many, many years and it was horrible to say the least, although at the time I didn't realise how difficult mainly because I don't ever remember them living together.
The tension was the worst and because they wouldn't speak to each other or be in the same room together, the grandchildren (during visits) would be asked to be the messenger between them.
As horrible as it was, they both showered us with lots of love, cuddles etc and made sure we knew they each loved us heaps, but when I think back (as an adult) their lives must have been pure hell trying to keep up the facade. Anyone outside the family 'thought' they were still together.
So from my experience I would suggest a total separation. I also agree with Spice101 in relation to kids inheritance, it's a gift not a right and if there's a gift for them at the end of your life, so be it but in the meantime you need to look after yourself.
All the best ;-)