Macbook A1342 Shuts down when releasing keys

my problem isn't quite similar, but still it is vey frustrating... I own a late 2009 A1342 macbook 6.1 unibody which was diagnosed as brain damaged and followed to be thrown off into the junk jar :( and I said NO! so I saw myself onto a personal challenge and a duty to restore the machine and put it back into a useful thing... so it's been about two months since then and this is more or less what i can tell you about:

Original Specs: -No turn on -No chimes

Primary AID: took the HDD out and erased it from disk utility on another mac in Mac OS X Plus (Journaled) --> Nothing (hereby --> procedure)

Second Try: I performed "jump start" removing the keyboard flexible from the bay and made a point of contact at the seven -or so- pin (which is basically where the power button is located) to my surprise the computer did started and as normal showed the "unknown bootable startup icon" the one with the interrogation sign on a folder... SO i performed a clean installation of Lion and -already knowing- at the moment of putting some personal data like names and such I realized that the keyboard was damaged due to a water spill.

I changed the keyboard entirely with the top case, THIS worked... BUT I started having SUCH an issue when loading the apple icon on the booting dialogue which is SHUTS DOWN and I discovered that when holding up any key I was able to reach the complete booting process but if release this particular key (F6) it shuts down instantly... I changed the Magsafe power board due to an electrical failure and the problems are still present to this day...

The computer turns on by himself when shutting down and plugging off the magsafe cord... WTF, when lifting up the computer, when shaking (I know all this issues are associated to a SMC problem but wether or not resetting the problems persists... and I believe the computer won't even allow me to do it.

This is very annoying and frustrating at the time to work on the machine. And there is something weird about the admin privileges that won't allow me to copy or drop n drag things to the Macintosh HD main route without authenticating the user password... and again WTF??

Please guys if you lend me a hand i will be very grateful with you... in other words HELP!!!