"Itchy" and "Lumpy" are nicknames, just like "Chewie" is. Look it up!

There wasn't a whole lot of canon on Wookiees back in 1978. But Chewie isn't a total primitive as originally conceived, and it's silly to assume Wookiees don't have the basic comforts of home.

I don't know of any 20th century dwellings that look like that, and happen to be in the top of giant trees though. (Nor do I know of anyone who had holographic displays, video communications, or virtual reality porn devices in their homes at the time.)

Ralph McQuarrie designed the Wookiee home, so blame him. ;)

The Wookiees all wear red gowns at the end to conceal the fact they only made new costumes for Chewie's family. In fact, all the extras are wearing modified Don Post Chewie masks!

No major network or studio would shoot a tv special on U-matic in 1978. It was probably one-inch broadcast tape on a reel. U-matic was what colleges and cable access channels once used because it was cheaper than most broadcast gear. Some news broadcasts used it early on for it's portability in the field.