I'm pretty sure the cloud contact center solutions listed below allow you to dial mobile numbers. As for system control typically speaking you are given some sort of interface which gives you control over the services you paid for. You can typically access those services on the interface. What interface you get depends on who you are working with.
are their countries that do not have the infrastructure to support cloud?
You should be fine. In lay terms the cloud is just a fancy way of saying "server farm located somewhere where we rent space and services" If it works for you it's going to work for a cloud provider. Honestly act interested and talk to a few vendors and their sales people will basically bend over backwards to try and explain exactly what they can do for you.
