Full wing "wild" geese do not have to run to take off. They can and will jump straight up and with a hard down stroke of the wings be in full flight. You must clip, pinion, or build a large, fully enclosed aviary. Geese kept full wing in an aviary have been known to hurt themselves by flying...
No special fencing requirement different from any other goose. I do not recommend mixing the Canada's with Cackler's without first keeping Canada's for awhile. Canada's get pretty mean in the second spring of life and can really put a bad whipping on smaller birds (owners too).