I am a chiropractor and first and foremost it depends on your goals. If you want to treat back pain that is one thing, but going to the chiropractor is about a lot more. Regular adjustments can help to prevent your body from decaying, just like going to the dentist to prevent tooth decay.
Different people are different. That is why there are so many different options. Some people will receive benefit from one treatment more than others. If you've given chiropractic a fair chance, as in following your chiropractor's care plan, then with regards to treating back pain it might be an idea to try something else, physiotherapy or acupunture for example.
If you notice massage and yoga work for you, do those. Orthotics can help people with back pain as well. There should be no problem just having orthotics done with a chiropractor, many do them and if you have a good chiropractor then you should be able to say what you want and have that and only that. Not as many physiotherapists do them. You could also go to a podiatrist or foot doctor.