BMW 750IL, Engine knocking plus Much more..

I just bought a 88 bmw 750il.. Needless to say it is riddled with problems.. This is going to be quite a bit of work but after searching several forums i see that many repairs can be home done.

Anyhow to start off
it needs a new headliner, the small panel where the moonroof switch is looks like someone punched it and is in several peices, the moonroof will lift up and down but will not move forward or backwards(tried a different switch and it wasnt that), the rear lift of the passenger seat twists it(not very concerned), the "recline" function on the pass seat gets jammed and clicks a bit (oddly enough if you can get it reclined back just a bit it will go all the way down and up just seems to jam up at the upper position), the driver seat will not move forward or backwards (reads a voltage at the motor so i assume its bad), the fan switch doesnt work unless you turn it all the way clockwise to the High setting, the driver arm rest is gone, one of the lenses is missing out of the rear pillar light, the right rear back seat is missing the plastic panel and all the switch covers, one of the fog lights is busted and the little vent covers in the front are long gone, and the abs light is on.. Whew!

Now here is a Very strange when we got it home i notice several fuses blown.. we replaced them and two blew right away, the 30A heated seats fuse and the 10A right side running lights and interior lights fuse. I thought it was strange that it worked for a small amount of time and when i pushed the lumbar support button on the driver side it blew.. and blew every time from then on.. and once i got the 30A fuse to work for a little bit and the dash lights came on nice and bright until i hit the lumbar button. hehe after that it would blow them every time. I unplugged all the connectors under the driver seat towards the front in a black box. and nothing... So i spent quite a bit more time trying to figure out what was going on and found one more connector towards the back of the seat (maybe 6-7 wires), after unplugging that connector the two fuses under the hood did Not blow anymore. now everything works and it apears both seats have disfunctional heated seats and the driver side has no lumbar support (i might add the lumbar is at max and is terribly uncomfortable).. Very strange, i need some tools and i need to take the seat out to address this problem and the front/back movement motor.

To continue on the problems list, the engine apears to knock/click and it is there whether the engine is warm or cold and it speeds up as you rev the engine, it sounds like it is comming from the top of the engine. This worries me and might be the first to adress. Any thought on if this is important to fix right away or could i just drive it as is? I would like to mension the previous owner drove the car pretty hard and used regular unleaded instead of premium. It has 205k and i have no previous history on it, so i dont know if the transmission will die tommorow and if it does, its all over.

I bought this car to have some fun with but it does have its share of problems. I really dont know how to check everything out and i know these cars require alot, but i would like to slowly fix things and hope to get it into tip top shape. :-). Any suggestions or thoughts to help me on my way?
Thanks

Regular gas is fine for the V12 engine. No problem.
The heating problem: if the fan only blows when you turn the thumbwheeel to max over a certain resistance, then the "sword" is defective.
Go to may page and read all the links. There are wiring diagrams, and a lot of other pages how to repair.
The sword thingy is shown on the e34.net.
And the seat twisting problem is shown on Gale's pages.
There are a lot of things, but they can be solved. First start reading all the links in my website and then you have a more clear picture what has to be done.
If still something is unclear, just ask, there are a lot of people with a lot of knowledge.
Good Luck with your repairs.

PS: Headliner I have done abt. 3 months ago. Just go to my website, there is a nice description and a lot of pics.
Not so difficult, but takes one day to do it. Better with 2 people.
The 750iL has larger doors at the back, so it is much easier to get the headliner out thru the rear door.