Changed it from Expert to the lowest. i changed every option for difficulty to the lowest, left the barrow, waited 15 days and went again in. No change. Even after starting a new game. i made now a new profile, played until i left helgen without mods and then added one mod after another and after every 5 mods i made a new reproccer and bashedpatch/tes5edit merged-patch to see if it influencess the ID or Health. So... i still get enemys with the ID of 8000000 but they are now as strong as they supposed to be. Loadorder in the left and right window of mod organizer are the same as before and i didnt reinstall any mods....i dont get it, but it seems to work now properbly. -.- Before that i checked Tes5Edit and found nothing suspicious. I filtered conflicting references and the creatures with the 8000000 ID ingame had normal stats. Long story short: i dont understand what the bloody hell i was doing wrong. :D But thanks Darkened666 for your help. :)