Here's the thing: you have the right to complete, objective information about your options so that you can make informed decisions, and the right to make an informed decision includes the right to informed refusal. As I read your post, you have two questions: One is "What is the best estimate of the risks to my baby in my specific case if I leave the hospital altogether and how likely are they to occur?" I say "your specific case" because your baby's estimated weight and condition should be factored in as well as such things as your distance from the hospital. This equation changes, of course, as time passes. Factor in as well that most home birth midwives confine their practices to women who do not have medical or obstetrical problems at onset of labor, which would preclude preterm labors. The other question is "What care do I agree to while in the hospital?" It isn't, as it appears to be, an all-or-nothing issue. You could refuse any monitoring and interventions for which, after hearing the pros and the cons, you think the harms outweigh the benefits--and your mental distress is definitely a harm that should be counted as a "con."
Here are some useful sources from the Childbirth Connection website: The Rights of Childbearing Women, and Informed Consent, Informed Refusal. And if you need a bit more muscle, here are your rights according to HIPAA, which is a set of government regulations:
This is an easy one. It isn't up to you to find research that supports not doing NSTs; it is up to them to show you research that supports doing them. If they can't show you research that NSTs improve outcomes of babies born preterm--and I will bet the mortgage they can't--then you are home free. Keep in mind as well that the argument that they don't do any harm isn't good enough because NSTs aren't harmless. As with all fetal suveillance tests, they have a high false-positive rate, that is, the test says the baby has a problem when the baby is really fine. This means you could end up with an induction and a premature baby or cesarean surgery that you didn't actually need. And, of course, there is your ongoing stress, which isn't good for you or the baby.
If I am wrong, and research exists, you may wish to rethink your position--or not. Your right to informed refusal doesn't depend on anything but your own judgment of your situation.
If you want to stand pat, I think your best bet is not to let yourself get drawn into arguments. Just keep politely insisting on your right to informed refusal of NSTs. You may also need to make clear that you are not refusing any and all care and monitoring if that is not the case. You could, for example, refuse NSTs while agreeing to monitoring for signs of infection. Also, make sure that anyone close to you to whom medical staff have access are on board with you. It isn't uncommon for staff to attempt to co-opt them.
Also, in your evaluation, you may want to include the risk of infection by simply being there for so long.
As far as fetal monitoring, can you just do a movement count at the same time each day? This should give you a good picture as to what is normal and what not and if baby is fine. No need to stress him/her out either.
What foods are you eating in the hospital? You should be eating lots of probiotics, zinc and vit. C rich foods, for you immune system and the amniosac!