Gawd thats a big manual...
Didn't actually help much though, only bit of useful info in it was that It doesn't support interlace mode, but that shouldn't affect the picture on bootup as the initial screen should be Med-res (640x256).
I've only seen this problem with an Elion DVD recorder I have, much the same picture quality and disturbances you describe here. The (almost !) solution to that was placing 75ohm resistors directly from each of the Red, Green and Blue signals directly to ground. It improved the picture greatly but there were still some annoying flicker left over. The Amiga's RGB signal it gives out is quite a strong signal and for a few TVs and DVD recorders the placing of the 75ohm resisters usually clears up this problem.
However I don't know your skills with a soldering iron or making up cables/connectors but other than giving the above a try I don't think I can be of much more help here...sorry....
As I mentioned it improved the quality greatly on the Elion DVD recorder and upon further investigation inside the machine, I found that anything going through the scart socket was being processed first by a small circuit board, upon tracing the input signals I eventually bypassed this board and this resulted in a perfect RGB picture, but I don't think you want to go dismantling your telly in the hope that you could do the same with it...
