Magnets and Lasers, are they for treatment?

Short answer: Magnets, No.  Lasers, depends on the kind and manner used. 

First, Magnets.  There are Chiropractors that will use magnets to treat.  They claim that these magnets will keep your electromagnetic field in check and will keep you from getting a disease.  Some will claim it can even cure one!  This has been proven false time and time again.   You want to see some good articles proving it's false, go to this link:  Magnet Therapy.  When people wear these against their body and report feeling better, it is ALL placebo.  Most of the time, we will take a Doctor's word for it, and not question it.  But I could recommend a piece of plastic, or any other randomized object, as a form of treatment, and many people would report getting better.  Again, the placebo effect.

Now lasers can be different.  Cold Laser therapy is something that is widely used today in Chiropractors offices.  It is called Low Level Laser Therapy, or LLLT.  This is a legitimate form of treatment.  Basically, with a true Cold Laser, the light energy will penetrate the skin and bombard the mitochondria of cells.  These 'powerhouses' of the cells will respond to the light energy by producing more ATP.  This will be used to help heal, build tissues and 'dissolve' the pain.  This therapy is widely used by Pros in many sports.  Now, the second the Doctor starts to use it to 'cure' allergies, to change mood, 'interrupt' your electromagnetic field, or for anything besides swelling, bruising and pain, you should be leery. 

Applied Kinesiology, Fact or Fiction?

The short answer: FICTION.  Applied Kinesiology, or AK,  is a form of Manual Muscle Testing, or MMA, that many Chiropractors use to 'diagnose' a disease or condition.  They will tell you to hold your arm out and then they will test it's strength using certain 'protocols.'  Sometimes they will ask you to hold an allergy vial, or hold little bottles of minerals, and sometimes they will test you for allergies to air!  Supposedly they can diagnose ANY condition conceivable to man by testing your muscles.  Sound impossible?  It is!  Time after time, legitimate scientific studies have proven that AK does not work as reported. 
Some of my friends have gone to an AK Doctor and have told me that they really feel week in that muscle when the Doctor tests it.  There are a number of reasons for that action.  First, most times the amount of pressure applied by the Doctor will vary because of what they are trying to 'diagnose'.  The most important reason is because of ideomotor action by the brain.  Check out this website:Applied Kinesiology.  You can see what experts have proven about this pseudo-science. 
Finally, don't get me wrong, not all Doctors that practice MMA are wrong.  Manual Muscle Testing is an important test in determining if nerve supply is impeded.  If you test weak in a certain muscle, it could mean that you have nerve damage, or something to that effect, or it could simply mean you are out of shape.  Also, the study of Kinesiology (not APPLIED KINESIOLOGY), is a legitimate science.  It studies muscles and their movements, strengths and ranges of motion.  If you want any further info, let me know and I will be happy to talk/email you more.