Question 2
When a branch is taken as a cutting, why is a piece bearing no buds, flowers or fruit more suitable?
The right answer is the one marked above.
Anything it is still feeding draws on the food store it needs for growing roots. The cutting has no roots yet, so it cannot replace what it spends.
The cut end takes up water perfectly well whatever the branch is carrying, and weight is not the issue. The idea that the buds would compete with the first plant gets the biology backwards — buds growing is what you want, once there are roots to support them.