No, shutting down fiat payment flows does NOT devalue a currency intrinsically able to route around such problems. Furthermore making it more difficult to obtain does not decrease it's value.
Frittering away market value speculatively just at the time when big investors may be looking to come on board, does.
Yes because we should all blindly believe that Bitcoin is immune to crashing. You can't "route" around anything without centralized exchanges. Are you serious with this stuff? Were you even paying attention yesterday? It's only worth what people say it's worth. The moment it becomes impossible to get any money out of the system (back into fiat) that's the moment it becomes near worthless. But that's the gamble right? Everyone can't be bulls.