Like Juli said you have to decide where you want to settle.
It's not cheap to move a household from NS to AB. Then you would be looking at the expense of two practice permits in one year. Yes, you have to pay in each province you are permitted to work in, so most Canadian nurses only pay for the province in which they live and work.
Despite holding a NS permit, CARNA may decide you don't meet their educational standards and still require you to do upgrading.
It's isn't an endorsement really. When you move interprovincially, the new province goes over your education and work history and decides if you are qualifed to work there.
AB and NS are two very different places to live in. Each has their drawbacks and selling points. However, neither one is really calling out for nurses.