Personally I think Froome is clean but I can see why some are suspicious (and if Froome was a Kazakh rider for Astana I’d be suspicious to). I have a hard time believing Sky (with all their links to BC) would risk doping within the team and I don’t think Froome could get away with it without the team knowing.
As for his performances, the problem with him in the TdF so far is he hasn’t had a bad day yet and he’s always finished looking the strongest of the GC contenders – that is certainly unusual (for a clean rider).
His Dauphine performance was understandably more credible IMO, the days when he attacked hard he suffered the next day, I’m a bit surprised we haven’t seen the same so far in the TdF – although the 4 Alps stages might be when it happens. Unless the 4 other main GC contenders really are sick or strangely out of form it’s hard to understand how he can be so dominant day after day.
I hope he wins and I hope he’s clean – British cycling would take years to recover credibility if he wasn’t