Natural supplaments like sam-e, 5-htp, st johns wort are good for depress, anx & mood. Can all be taken, or just 1 or 2? I'm not on prescrip meds.

Perhaps but caution. Each of these has been shown to work as well as prescription antidepressants, but just as i would not start someone on 3 meds at the same time i would not start all of these at once; it will probably not be necessary and you could wind up with too much serotonin, which can be toxic. My favorite of these is 5-htp, usually 200-300 mg, esp. Beneficial if you have insomnia &/or anxiety. See my comment.
Be Very Careful. I never endorse starting multiple agents at once. You'll never know what did what. St. Johns wort is notorious for interacting with other medications. 5-htp can also cause serotonin syndrome if you use too much of it, or use it with other serotonin drugs. Though not on other drugs right now, i would recommend being monitored by a doctor anyhow to ensure proper dosing & minimize adverse effects.
Less is more. Treatment of anxiety and mood vs treating these entities as disorders is important to differentiate. Both can be a normal response to stress so before treatment, frequency, severity & impact on life should be evaluated. These products are helpful in milder symptoms, have limited double blind data and combinations are not recommended. Serotonin syndrome can be dangerous. A psy eval is recommended.
Not sure. I am not clear with what you are trying to treat. Best supplement for moods & focusing is omega 3/ fish oil. The ones you mentioned are supplements to elevate the mood & should not be combined with antidepressants.
Depends. The research is lacking on some of those you mentioned, but st. John's wort at least has some data to support a modest benefit in depression (although case reports of it making depression worse are also out there). I'd suggest trying only one at a time and let your doctor know which one. That way, he/she can monitor you for side effects or worsening symptoms.
All at once? All these chemicals raise serotonin in your brain & basically do same thing, to releive depression & anxiety. Would advise one at a time.
Supplement. Would not recommend together, since they all raise serotonin levels, and if used same time, can trigger serotonin syndrome.