I began doing some clicker training when Kenzie was young but it became difficult after he became blind because he can smell the treats and get to focused on them and totally ignore the clicker and me :P
#4 I actually don't need to do much accommodation because he have a great inner map in his head :P If I move things around I just talk to him and he knows things have moved. And I never close my door to the bedroom because he runs and hides under the bed when scared of something and I always have the backdoor fully open when he is outside in the garden if something get scary and he runs inside.
He jumps up and down the sofa and bed (only I that's thinks it scary when he is about to jump down my bed ;)).
But he now exactly where he is so no problem moving between home and the summerhouse and he loves exploring new places :) And he now exactly who is visiting (for example he can lay around sleeping while my nice is running around shouting and jumping and throwing thing but as soon he hear someone footsteps he is not familiar with he runs and hide :P
He had more problems in the beginning when he still had some sight. Then he run in to things and got easily scared of movement because he still tried to use his sight (had to put a bell on the dog so he could hear him better and not get scared when the dog did sudden movements, later he used the dog for navigating around by putting his whiskers against the dogs leg and follow him around) as soon as he lost the sight completely he used his hearing more.