You are correct on all counts. We've had to be so non-threatening that we haven't been able to train her more than she wishes it. She will sit for a treat and chase a bone, which she does not return. She understands NO and BE EASY. she's just to herself. she is a country dog who roams and we need to get her in the car to vaccinate her.
If you are in a rural area, ask your neighbors with livestock what vet they use as most vets treating livestock make house calls and will likely not mind vaccinating your dog once you explain the situation. However, if your vet will agree to a sedative, then you could just take her in after she is sedated and release her once you are back home. However, if you really want to try and domesticate her, you should try and get her into the house for an extended period of time so she depends on you and learns to trust being around you.
It basically depends on whether you want to be closer to her in which case, bring her inside and if you don't mind her being an outside dog, sedate her, have her vaccinated and continue to acclimate her to your presence when she decides to come around when you are outside. There really isn't any quick easy way to get her to trust you that your are not already doing in the present circumstances.
If you need clarification or I haven't been clear enough, please reply so I can continue the discussion. I hope this information is helpful to you and you are satisfied with my response.