Good news continued!
K-Meleon74 works stable on Windows 2000 (Excore v16 German, Exkernel v24bG localized German). First I installed K-Meleon 1.6.0 in w2k. Then I installed K-Meleon74 in XP32 (in folder programs\k-meleon74) and copied that folder into the w2k program folder. Then I started k-meleon.exe. It works fast and stable in desktop and laptop envirement (I tried with 5 different PC's). And can be customized to look like IE6.1.
Only on one machine I had to disable Direct3D (I think this is due to Radeon Driver and Directx Jun10, direct3D 8 and 9 are working, but 7 hresult 0x88760249 Get DC), otherwise screen was filled black in the browser few seconds after input.