[...] my questions:
1. what is the diameter of the spine?
2. does this kite comes with an end-cap at the lower end of the spine (opposite to the nose) or with a weight?
3. if the answer to question 2 is weight then what is the weight of the weight (funny but a real question)?
No weight needed for this allrounder kite.
For the spine, just place a ø 5 mm endcap.