with his powers? Can he use his powers to jailbreak games from the internet and use his powers to copy it down into disc, tape, DVD, BluRay, JumpDrive etc...?
Can he use his powers to tap into cameras and spy on people?
If his computer has a Trojan Virus, but he does not want to buy Norton 360, can he use his powers to clean or delete the virus off his computer?
Can Magneto use his powers to free more virtual memory RAM so that he can open more applications on his computer?
If Magneto started out with a 32-bit Pentium III computer, but is bottlenecking his time on computing his appications, can he use his powers to make the 32-bit CPU run faster or can he use his power to to turn the current CPU into a 256-bit 100Thrz CPU and turn a 4GB DDRAM into a 500TB XDRAM?
Can Magneto change the layout of his Facebook Profile to look exactly like his Myspace profile using his powers?
Can Magneto bend a tree using his powers?
Can Magneto's powers kill cancer cells?
Can Magneto see in the dark by altering the light of his eyes to like night vision goggles?
Can Magneto tap your memories by reading the electronic signals of your brain?
Can Magneto carry water using his powers?
Can Magneto rip your arms off using his powers?
Can Magneto turn invisible?
Can Magneto turn visible light into Gamma Rays or X-Rays and then back to visible light? 

I'm lumping all the computer-related questions into one answer: possibly. But he can't see through electronics, so the camera thing is out.

Now, starting with the tree question:

1. Yes. He can screw with the gravitational field.
2. I think so, yes.
3. I think he has.
4. I seem to remember an incident where he did something similar; not sure, though.
5. Yes. See #1.
6. Yup.
7. No.
8. I don't think so.

 with his powers? Can he use his powers to jailbreak games from the internet and use his powers to copy it down into disc, tape, DVD, BluRay, JumpDrive etc...?             Maybe.
Can he use his powers to tap into cameras and spy on people?                Yes and no.  He can not "see" through cameras, but if it's a digital feed, he should be able to electronically tap into the feed and manipulate it so he can see it on any computer.
If his computer has a Trojan Virus, but he does not want to buy Norton 360, can he use his powers to clean or delete the virus off his computer?    Yes.  See  Excaliber vol 3 #4.
Can Magneto use his powers to free more virtual memory RAM so that he can open more applications on his computer?                                                Yes.
If Magneto started out with a 32-bit Pentium III computer, but is bottlenecking his time on computing his appications, can he use his powers to make the 32-bit CPU run faster or can he use his power to to turn the current CPU into a 256-bit 100Thrz CPU and turn a 4GB DDRAM into a 500TB XDRAM?                                                                                                   ????
Can Magneto change the layout of his Facebook Profile to look exactly like his Myspace profile using his powers?                                       Yes.
Can Magneto bend a tree using his powers?                                        Easily.  In many ways.  Just off the top of my head...he can manipulate gravitons thus altering gravity around it.  He can manipulate it directly via diamagnetism.  He can use an EMP.   He can use free floating atomic metals in the air.    See  X-Men #12, Uncanny X-Men #112, New Mutants Vol. 1 #40, Uncanny X-Men #275, X-Men Vol. 2 #2, Excalibur Vol. 3 #14
Can Magneto's powers kill cancer cells?     Yes.  He can manipulate subatomically to just destroy it, manipulate iron in the blood to destroy the tissue, bombard it with radiation, etc...   It's no different than when he destroys the telepathically altered brain tissue in Rusty and Skids during Fatal Attractions. 
Can Magneto see in the dark by altering the light of his eyes to like night vision goggles?      No.  He can sense through the EM spectrum, however, and can perceive everything as pure energy.
Can Magneto tap your memories by reading the electronic signals of your brain?                        I've never seen this, but he may be able to.  He can destroy brain tissue with enough precision to delete memories from you though.  He can also attack astrally, which is indicative of tp.
Can Magneto carry water using his powers?                                    Yes.  Again diamagnetism.  It allows him to directly manipulate electrons. 
Can Magneto rip your arms off using his powers?                                Easily.  There are plenty of instances of Mags ripping people apart.  X-Men vol 2 #110 for example.    Iron in the blood, diamagnetism, graviton manip, take your pick. 
Can Magneto turn invisible?                                                                  Yes.  I don't remember the issue, but he did this when he invaded Attilan.
Can Magneto turn visible light into Gamma Rays or X-Rays and then back to visible light?        Theoretically...yes.  By accelerating electrons, much like a synchotron, he should be able to do it.  It certainly falls within his demonstrated range of powers.
If Magneto was looking at porn on his computer and Rogue suddenly walks in, can he wipe the history and cookies before she looks at the screen and takes over the computer using his powers?       Yes.
Can Mangeto clean out your Registry?                           Yes.

"  with his powers? Can he use his powers to jailbreak games from the internet and use his powers to copy it down into disc, tape, DVD, BluRay, JumpDrive etc...?             Maybe.
Can he use his powers to tap into cameras and spy on people?                Yes and no.  He can not "see" through cameras, but if it's a digital feed, he should be able to electronically tap into the feed and manipulate it so he can see it on any computer.
If his computer has a Trojan Virus, but he does not want to buy Norton 360, can he use his powers to clean or delete the virus off his computer?    Yes.  See  Excaliber vol 3 #4.
Can Magneto use his powers to free more virtual memory RAM so that he can open more applications on his computer?                                                Yes.
If Magneto started out with a 32-bit Pentium III computer, but is bottlenecking his time on computing his appications, can he use his powers to make the 32-bit CPU run faster or can he use his power to to turn the current CPU into a 256-bit 100Thrz CPU and turn a 4GB DDRAM into a 500TB XDRAM?                                                                                                   ????
Can Magneto change the layout of his Facebook Profile to look exactly like his Myspace profile using his powers?                                       Yes.
Can Magneto bend a tree using his powers?                                        Easily.  In many ways.  Just off the top of my head...he can manipulate gravitons thus altering gravity around it.  He can manipulate it directly via diamagnetism.  He can use an EMP.   He can use free floating atomic metals in the air.    See  X-Men #12, Uncanny X-Men #112, New Mutants Vol. 1 #40, Uncanny X-Men #275, X-Men Vol. 2 #2, Excalibur Vol. 3 #14
Can Magneto's powers kill cancer cells?     Yes.  He can manipulate subatomically to just destroy it, manipulate iron in the blood to destroy the tissue, bombard it with radiation, etc...   It's no different than when he destroys the telepathically altered brain tissue in Rusty and Skids during Fatal Attractions. 
Can Magneto see in the dark by altering the light of his eyes to like night vision goggles?      No.  He can sense through the EM spectrum, however, and can perceive everything as pure energy.
Can Magneto tap your memories by reading the electronic signals of your brain?                        I've never seen this, but he may be able to.  He can destroy brain tissue with enough precision to delete memories from you though.  He can also attack astrally, which is indicative of tp.
Can Magneto carry water using his powers?                                    Yes.  Again diamagnetism.  It allows him to directly manipulate electrons. 
Can Magneto rip your arms off using his powers?                                Easily.  There are plenty of instances of Mags ripping people apart.  X-Men vol 2 #110 for example.    Iron in the blood, diamagnetism, graviton manip, take your pick. 
Can Magneto turn invisible?                                                                  Yes.  I don't remember the issue, but he did this when he invaded Attilan.
Can Magneto turn visible light into Gamma Rays or X-Rays and then back to visible light?        Theoretically...yes.  By accelerating electrons, much like a synchotron, he should be able to do it.  It certainly falls within his demonstrated range of powers.
If Magneto was looking at porn on his computer and Rogue suddenly walks in, can he wipe the history and cookies before she looks at the screen and takes over the computer using his powers?       Yes.
Can Mangeto clean out your Registry?                           Yes. "