If government will show support over bitcoin I'm sure the economic status of their people will grow and also their countries. The reason why some government do not declare the legality of bitcoin is because they couldn't find ways to have control over it and they are afraid that if they will declare bitcoin as a legal tender some people or corrupt may use it for illegal purposes which they cannot control or determine. But if they will have control over bitcoin surely many will be benefited and many can have the opportunity to become financially stable.
This one is definite. First of all, it would create more awareness for the usage of bitcoin, hence increasing even the status of the people holding it already, as the value increases. Most citizens of some country suffering hyperinflation now are already finding solace in the usage of bitcoin and that speaks a lot of volume and over time, we will start seeing changes as the standard of living of people keeps getting better and hence helping the economy in general.
However, with respect to fraudulent and corrupt activities, I do not see how this cannot be curtailed if regulated and if exchanges are monitored. At least they will have to make use of an exchange before they even purchase in the first place and the regulation comes with anyone who wants to use an exchange going through the verification process, so with that, there is no way you cannot be nabbed. This does not mean some corrupt people won't always find their way like they normally have, but the usage of bitcoin won't definitely improve it.