Can those colored parts pivot or turn while still attached to the pipe? I mean on the model, not necessarily in reality. Is it easy or does it require way too much readjusting?

Good question i don't have a real awnser to. Am still learning how all those models their bones work in sfm so for now i whas able to easely work with them as you seen with the latest one i made , however it require multiple angles to pose them correctly in. Once i get a better understanding in it i hope i can find a reasonable point you can rotate with.
The attatching to the pipe is done in sfm so normaly those parts move with the pipe ( if done correctly ) However those should be able to turn seperatly.

Neat! Sounds like a hell of a lot of progress though.

It is if you don't know what da hell you doing , like me XD

Looks really nice! i like how you got the textures to work XP how they all fit looks really clean too!