5 is the only one that seems practical, although it isn't actually serving any purpose. The bike is still taking up the same amount of space, with the added difficulty of having to install the hardware. Aesthetically could be great, however.
You designed these? You need to start way, way back, unless this is strictly blue-sky ideation.
1) What is the problem that needs to be solved?
2) What are the existing solutions?
3) What are the problems of the exisiting solutions?
PM me if you want to talk about this stuff.