How many bupivacaine injections in the right scaplothoracic region are safe at one time? Is 8 ok? Are flu-like symptoms cause for concern?

Depends. You need to discuss the risks/benefits of multiple injections with your doctor. Depending on your condition, doing several injections, if beneficial, may be acceptable despite slightly higher risk. That decision needs to be made mutually in the clinic before the injections.
Count total amount . It's not the number of injections, but the total amount of bupivicaine safe - usually, up to 1 mg per lb is safe. Flu-like symptoms suggest a mild allergic reaction, so it is safer to use a different local anesthetic. If bupivicaine is used for trigger point injections, Lidocaine can be as effective, even if it is a little shorter-acting. Consider Botox if the tp inj. Have to be repeated often.