Are you absolutely sure, that you don't have the cam belt pulley off by a tooth? have you actually measured the cam timing? Same with ignitoin timing have you actually measured it? I hope you did that with the vacuum hose disconnected.
If you want to rule out the knock sensor you can unscrew it and put it away somewhere, but still connected to the loom. Then plug the knock sensor opening in the manifold with something and give it a try. If you get more power, then it's the knock sensor limiting the going. You can't just disconnect it as that will make the ecu go crazy.
Does someone know for sure, does the knock sensor effect ignition timing, Åmål-valve, or both?