On the Steve Jones course, he actively recommends that any person with a mental illness should not be treated by a newly qualified hypnotist. Such a person should be referred to a medical professional. It is one of the very few exceptions to the long list of people who can be helped by a hypnotist. See
http://www.webmd.com/anxiety-panic/g...h-hypnotherapy
Mentally ill people are best treated by a psychotherapist. There are risks involved with mentally ill people. For example, if a person with clinical depression committed suicide after a session with you, despite your best efforts, you could be legally liable. Or if you tried regression techniques with a mentally ill patient, repressed memories could be unlocked, with unpredictable consequences. It is a very specialised area, and certainly not one for a beginner (and not one I would care to risk, either, with an advanced certificate). I personally believe that hypnosis could benefit a mentally ill person, but only in the hands of someone who has intimate knowledge of mental illnesses as well as hypnosis training.
In the case of physical pain, hypnosis can indeed be beneficial, but caution is still needed. For example, if a client comes to you with a terrible headache, you could hypnotise him/her and give suggestions that the pain has gone - and it would work. But what if that person has brain cancer? You could be masking symptoms which need attention. So in such cases, I only help people where the physical symptoms have been investigated and the is cause known. For example, I know a lady who has been diagnosed with a deformed spine and has severe pain - and all the doctors can do is give her more morphine - which clogs her brain and she complains of memory loss as a result. So in such a case, hypnosis can help with pain relief and make her life bearable, without excessive strong painkillers.
I hope these two examples help you to see what you can and can't (shouldn't) do.
Regarding your course, it seems expensive to me, but if you have the funds I suppose it does offer the benefit of three days' practical experience.
I looked at the brief video on the page you mentioned, and I wasn't very impressed with the rapid induction used. It looked fake to me. Rapid inductions can work - but this somehow looked contrived. In modern hypnosis, this sort of showy, dramatic induction is rarely used, except with clients who are over analytical. It is sometimes used for stage hypnosis - but you don't need that!
The orthodox type of hypnosis is normally by the relaxation method, gentle and calming. There are lots of other inductions, but they are all fairly gentle. This is important, as it helps a client to settle into hypnosis in a calm state, not one of shock.
I would think carefully before committing yourself to this particular course. I would also recommend
extreme caution about seeing mentally ill people for hypnosis sessions, even if for free.
I send you my very best wishes in your desire to learn hypnotism. It can be a power for good. It can help people in so many areas of their life.
Why not try Steve Jones' course online? It is inexpensive, and although it does not have any hands-on practical sessions, it will show you the basics and then you can decide if you want to go further. You can read about it at
http://www.hypnosiscertified.com