The ferris wheel at DCA is also just the backdrop for World of Color, but it got an extensive renovation in preparation for the show. It got a new paint scheme, that awful giant Mickey head, a new name, and snazzy new lights that are used for the show. Given that we're expecting the Tree of Life to have a similar impact in this show, and it desperately needs some love, I would expect it will get some work done
If they really want to push Rivers of Light and Avatar as the rebirth of DAK, I would expect extensive refurbishments park-wide, similar to Project Sparkle at DCA throughout the year-or-so leading up to the opening of Carsland and Buena Vista Street
There will be. All forms of entertainment with designated viewing areas (parades, shows, etc) have special areas for handicapped guests and their families. For WOC, it's located in the highest tier of the viewing area, but can be accommodated anywhere (since the views and impact of the show is different from different spots); assuming this has a similar viewing area, I would expect a similar considerations would be taken