Fix the Adsense ads before you get banned. Some of the navigation menu is hidden thus causing the Ads By Google to disappear. Against TOS.
That is far more risky than your original concern ... As long are you are not getting excessive clicks on any one site I can't see a problem.
well, i guess this is a problem. It does not matter in my opinion that there are different sites, but the problem is that there is the same adsense id and therefore looks suspicious.