If you stop fermentation (by freezing the cider?), they won't bottle carb.
It's very hard to make a sweet sparking cider without extraneous measures like pasteurizing, kegging and force carbonating, etc. The yeast will ferment what they will ferment, and won't stop because you want them to. They don't know the difference between priming sugar and the sugars added to sweeten the cider.
If the cider is fermented dry, and is finished, then adding priming sugar to carbonate isn't an issue at all and has no risk of bottle bombs.
Making a still (non-carbonated) sweet cider is easy as well, and would require stabilizing the cider once finished and clear with sorbate before sweetening. There is a cider "sticky" thread above this thread, called 'cider for beginners' that could be helpful with the specifics of this.