1. Brachial plexus MRI, since the lung mass is in right upper lobe and her pain is in her left arm. Metastasis or lymphadenopathy might be the reason causing her left arm pain. This infor will help whether radiation should also include left neck base.
2. I would definately get tissue/pathology diagnosis. We probably know she already has lung cancer and there are at least 4 cell types. Different cell type response to radiation AND chemotherapy differently.
3. But I would not do bronchoscopy since there is invasion to the chest wall. They can check sputum or a biopsy through the involved chest wall guided by CT or x-ray fluroscopy. This can be done with local anethesia with minimal discomfort and chance of complication when performed correctly.
4. I would definately work her up to exclude distal metastasis because that will change the whole plan. Here in US we use PET/CT and any metastasis >= 1 cm will be picked up by the PET. I do not know what they use in China (be here for 10 some yrs). But a CT with contrast of the head, abdomen, and pelvis will be the very basic exam I would order. You will know the whole picture of her condition by doing this. This money will be well spent.
5. Then discuss with local oncologist regarding therapy. I would keep Chinese medicine an option or an addition.
Best of luck!