Strider episodes in Newborn twin

My 3 week old twin daugther was born with breathing problems which initially caused them to tube her and air-evac her to the NICU at the children's hospital. They have since done a whole lot of tests, but have come up empty as to why this is happening. Apparently her lungs are anatomically perfect and nothing much else could be found. Part of the reason for that is that she is/was under anasthetic while these tests happen and when she's relaxed there is no problem, so really the only thing that can be checked is anatomy but nothing much else.

Her symptoms are the following: When she gets upset, ie she starts crying, she will go into a strider episode. The strider noise is only audible on inspiration, she gasps for air, her little chest "caves" in and it sounds like she is breathing around an obstruction. Her face will go bright red and she'll start to perspire on her face and head from the effort of breathing. She responds to being comforted, held tight, put on her stomach etc. In addition what needs to happen in order to keep her from turning blue is blow by oxygen (and oxygen mask by the side of her face rather than on her face).
I have also noticed the following when her strider episodes start. It will be hard to explain but here it goes anyway. While holding her it feels on her back (and it also sounds like) a "lid" or valve is "going the wrong way". If I were to make an educated guess I would say that either somewhere in her voicebox or the lid to the epiglottis is not hardened enough or the muscles are too floppy which causes them to "collapse" into her airways when she gets upset, ie when her breathing becomes more rapid. However, this is just my feeling and has not been confirmed in any way so far.

In addition to all the above we do have a couple of new symptoms since yesterday, which have made everything somewhat worse. She appears to have reflux, which means that her food comes back up about 1/2 and hour to an hour after she ate. It comes up in a projectile fashion ... being forced quite far and through her nose to boot. Having her on an incline for feeding and for sleeping has not prevented this. Unfortunately she is predominantly on formula, only getting the odd appetizer of breastmilk (my milk never quite came in). When this throwing up happens she of course gets very upset ... and goes into pretty intense striders. The whole thing is made worse by mucus that is clear and frothy and so "sticky" that you can pull it for several inches from her mouth. Of course this makes breathing even more difficult and it appears like she is trying to breath through "bubble gum". Due to this her heartrate goes quite high (above 210), which causes the monitor to go off, which is a LOUD noise, which upset her more etc.

Generally she responds very well to touch ... any kind of touch, be it being held, stroking any part of her, massaging her feet etc will calm her down. When she is awake she does have noisy breathing, again only on inspiration ... like various degrees of "squeeking". When she is quite relaxed though or deeply asleep there is no noise to be heard. Other than that she is a very alert and happy baby.
She is not the most patient baby - again probably due to her inability to relax. She also visibly relaxes when she is put together with her twin brother. She appears to be somewhat more bothered by noises these days.
She was born somewhat premature (35 wks) via emergency c-section. I was severely pre-eclamptic and that also means that unfortunately my babies were exposed to a LOT of medication.
She spent 2 weeks in the NICU in the hope she would "snap out" of the striders or we would find a definite diagnosis but none of that has happened. Once I got her home I did administer Arn 200 as the little girl seemed in shock more than anything else and was quite weary of being touched. As mentioned above ... this is no longer the case.
She also responded well to Puls along the line, but not drastically so -part from anything else, she does NOT have thirstlessness going on ... she will eat/drink quite a bit .... in big gulps if allowed. I have since put her on a feeding system that slows the milk down some and makes her work harder for it in an effort to not overload her stomach. For now it has worked ... but it has only been two feeds since, so can't be sure yet.
Another thing is that even though she is somewhat impatient and does get upset easily, she does not appear to be angry (so I ruled out Cham and am weary of Bell) ... she is probably more "uptight" and anxious rather than angry.
Other than that she appears to be thriving, having her gained back her birth weight and an additional 1 lb and 11 oz. She also poops and pees as she should.
Oh one maybe more interesting thing is that she likes to work her feet out of the swaddle ... they are always a priority. They don't however appear to be unusually hot or cold, she just seems to like them out of the swaddle, but not out of the blanket.

Sorry this turned out to be so long ... I wanted to be as accurate as possible. Any help would be very much appreciated. I just don't have the objectivity at the moment ... apart from also being severely sleep deprived - so I can use all the input I can get.
TIA.