Sorry for bumping this back up
I just noticed that several of my AMIGA-to-SCART cables I have flying around here have +5v wired directly to Pin 16, and +12V wired to Pin 8, and they all work fine with my pretty old Grundig TV.
So I got a little curious.
I remember I've seen several SCART pinouts that state Pin 16 only has an input range up to 3V, while others say 5v.
So I've started to fool around with several (older) TVs over here.
Actually it seems you don't need +12V on Pin 8 and you don't need +5V either.
EVERY single TV I've tried works fine WITHOUT Pin 8 connected to anything.
The only "use" of it is to switch between a FORCED 16/9 or 4/3 mode. Some TVs also power on and switch to channel AV by themself if you supply power there.
Also every single of those TVs worked fine with +5V feed to Pin 16 instead of just 3V.
None of the blew up or something like that.
Conclusion... Though it may not work with every single SCART TV out there, the absolut simplest VGA-SCART cable would be:
VGA - SCART
1 - 15 R
2 - 11 G
3 - 7 B
6 - 13 R-GND
7 - 9 G-GND
8 - 5 B-GND
13 - 20 Sync
14 - 20 Sync
5 - 17 GND
9 - 16 RGB-Switch
I've modified my VGA-SCART cable that way and have yet to find a TV that does not work.
Also a friend pointet out that you can connect Pin 19 (Composite Out) to Pin 16, as the Composite Video has a signal level of 1V, which also should be enough to switch to RGB mode.
However I haven't yet tried that.