Hi coasterhusband,
I have several big questions I struggle with:
good to hear

1. Is there any time in a relationship with a BPD person where I will be able to say how *I* feel about any topic of disagreement?
It is very important to express ourselves. It is equally very important to do it in the right place, time and in the right manner.
The reactive and often negative strong emotions of a pwBPD have a tendency to get the partner to not speak their mind. That is known also as walking on eggshells and a proven loosing strategy as over time not just the pwBPD looses contact with reality but both partners behave less and less rationale.
A key pattern to help you to get both grounded again is SET, see the workshop
here fore more. It takes time to learn but it is worth it not just for dealing with her but also extremely useful and versatile in all kinds of situations.
>> For instance: at dinner time, my wife claims my daughter is an unruly, misbehaving, picky eater. When I disagree with her and try to say "Honey if you give her a burrito as long as her arm, she might not be able to finish it all", I get the "YOU JUST DON'T UNDERSTAND! YOU DON'T LISTEN!" We've struggled with the dinner issue for our entire marriage, so I get that it's a loaded topic, but I use this one because it's fresh. Generally speaking, there is absolutely no room, ever for me to say "I hear what you're saying, but here's my perspective on that same set of events, let's talk about how we both can understand each other and figure out a happy middle ground". Instead, I just get "You don't understand me! I've given up my whole life for you [i.e. moving in with me when I have a daughter 50% of the time]! You have been killing me for years with this!"
Sounds she is upset and has been storing up some negative energy that is now released. Sounds also she is not fully in control of herself and the situation is escalating. In these situations there is NO opening for any rationale communication. The question is - will she calm down or do you need a timeout? Discussions running in circles are not healthy so after a few rounds it is fair to quit. For more on this check out the workshops on validation (helps calming down) and boundaries (timeout).
Generally speaking, there is absolutely no room, ever for me to say "I hear what you're saying, but here's my perspective on that same set of events, let's talk about how we both can understand each other and figure out a happy middle ground
I suspect you won't even get to the end of the sentence after you uttered "but". Do yourself a favor and strike this word "but" from your vocabulary. It links your side to hers and has the opposite sign. A reliable way to invalidate her. And that is most critical skill - avoiding unnecessary invalidation. Avoiding invalidation is more important than validation.
What you are trying to do is having her view, then your view and then looking at the common ground. A calm and rationale approach, debate style. But is it rationale to approach a highly emotional person that way? Understanding what it MEANS that you wife is highly emotional and what communication patterns work best is the key.
I find that the only way I can get from screaming/crying/complaining/accusing back to normal is not to try be calm and find rational conversation but to simply back away and admit fault and try to end the craziness.
Avoid lying to her just to please her momentarily as it erodes trust over time. She sure is happy that you end the fight and get her out of the corner she has pinned herself in but she also learns that you are not telling the truth. It is tempting and all of us do tell some white lies all the time if research is to be believed. The is a cultural bias even "how are you - fine". Still it is highly problematic in a relationship with a pwBPD. Focusing on validating exchanges is a much healthier and long term sustainable solution. It is also a big step getting honesty back into the relationship. Not an easy step for us as these troubled relationships require us to validate a lot of negative emotions and that takes some mind shift.
It's always some version of "it's my turn! It's always about you, so now it's about me!"... . but how can it be if we're always talking about her problems?
Am I kidding myself to think that at any time in my short term or long term future, she might say "I'm interested to hear your take on this"... . ?
You certainly have a good chance to voice your POV when learning SET. Still it may pay to take a step back and leave the YOU vs. ME dimension. She has a view. You have a view. They are not necessarily linked, adversarial etc... They are first and foremost justs views. When she has the floor leave her the floor. SET is also about claiming the stage for telling how you perceive the world but that can be at another time - a time of your choosing and not hers. Just because she is stepping forward now you don't need to have a
debate. Think of discussing with her not in terms of negotiation but in terms of offering your views to her to process. When properly framed in SET they are least offensive and also quite solid.
2. Is it common for a BPD to be completely incapable of admitting fault? I think in the 5 years I've known my wife, she's maybe say some version of "I was wrong, you're right" 3 times... . 4 times? Maybe? The best I typically get is a sideways knowing glance that says to me that maybe she's considering that she's not always right.
I don't know if this was something from her past and being always told she was wrong that she now fights back so hard or what. But am I crazy to think I'll ever get recognition from her that her way isn't always perfect, that in order for our relationship to flourish we BOTH have to admit fault where fault exists?
PwBPD struggle with processing emotions and processing guilt is not a preferred past-time for anyone. If easier cop-outs are available like blaming it on others then... .
But then, yes you are not rationale if you believe that she has to admit mistakes for the situation getting better. Deep down she likely knows that she made mistakes, possibly beating up herself over it much more than you ever could do. Having her to admit is, is advanced territory. It may happen but when it happens it is often major progress elsewhere that leads to her being able to be open about her weaknesses. For the time being owning up to your own mistakes (and not admitting guilt when innocent) is the best you can do here.
Her mistakes and errors are often linked to her thinking being emotionally too clouded or being even dysregulated. Avoiding invalidation, validating her and having boundaries that protect you against mishaps on her side are the first steps that lead to near term improvements.
3. Any tips on dealing with the "... . yeah but you do the same thing!" reaction?
She is baiting you for a debate. Don't pick up the gauntlet! (see also workshops on boundaries)
4. Is compression a common thing in conversation? Meaning: She takes one thing I say, and another thing I say (even though there may be tons of content and/or time in between) and compresses them into a false statement about what I've said. Then runs with that.
a) Possibly related to splitting which is a fragmented perception of reality. In that case treat it as a warning signal that she is on the path to dysregulation.
b) Possibly just a sign of her valuing expressing her emotions way over expressing accurate facts. In that case focusing on the underlying emotion and ignoring her words can be a good way to react. For more see the workshops on validation.