tbart, it's good you are seeing the difference between validate and doormat. It took me too long to learn the difference and I was confusing validate with submitting. It's not about submission at all.
The fact is you can't argue with feelings. It's impossible. If I tell you I feel you were never there for me, you can give me every single example of when you were - it doesn't matter because I still feel that way based on my perception (valid or not).
Validating doesn't mean you agree with her either. It's just you acknowledging you heard her position. 'I see you feel that way' in no way translates into - 'and I feel the same exact way'.
Don't fall into the trap of 'future talk'. Future talk is just that - words. Don't put any value on them. Believe me, I know first hand. Also, don't put any value on talk of separating, divorcing, past, future, what she wants to do, how long she's been thinking about it, etc...
MySitch Me-47 STBXW-41 D-5 S-8 ILYBNILWY-01/08 Want a D- 01/09 Physical Sep-01/10 D filed-06/10 Got 50% custody=09/11 Ride that wave!