Strange noises on my E53 4.8is

[bmwktm]

Hello everyone,
i just got me a 2004 E53 4.8is. This is my first V8 car.. i had several BMWs in last 10 years (E30, E34, E39) and E53 was the next logical step hehe.
The car is unbelievably powerful, nice interior, nice color, not so thirsty (if you are careful from time to time) BUT i have two noises i do not like and my indy is ensuring me that is nothing...
Here is a video where you can her both noises:
https://www.youtube.com/watch?v=0ZQtWJSaCDw

So the first noise:
That was first ignition after 12 hr of being stationary. Beneath the car you can hear grinding noise i think is coming from the transmission (correct me if i am wrong). After about a minute the engine stalls (probably oxygen sensor reaching temp limit and changing fuel settings?) and in few moments grinding fades away and does not come back.
Other scenario which is not on this video: i start the engine after 12hrs and after 2-3 secs i turn it off.. wait for 5-10 secs and start it again and than there is no grinding noise.
My conclusion is that oil is not getting immediately to all places it should... Previous owner said the oil in transmission, transfer box and diffs has never been changed.. so i hope this problem can be solved with simple complete oil change in the drive train? Also in DIS software i am getting a 54C6 error for oil thickness in the xDrive so i really hope oil swap will do the trick.

And the second noise (N62 engine):
in the video at 0:55s you can hear left side (drivers side), after that right side with knocking and at the end again left side. I think the sound is coming from the right head, something with the valves.. maybe hydraulic lifter?
When the engine gets to a normal temperature this sound gets quieter but it does not go away. I don't think it is an alternator issue because it is on the right side, and i don't think it is a/c compressor issue because the sound does not change when i turn it on and off.

So my questions are: HELP!