Answer:
Digital white-out.
What word sounds the same even after you take away four of its five letters?
With three leaves, I am just a plant. Add another leaf and everyone will want me for good luck. What am I?
Six letters do my name compound; among the aged oft I'm found; The shepherd also by the brook hears me when Leaning on his crook; but in the middle me divide and take the half on either side each backward read a liquor tell ev'ry gay toper knows it well.
You hold my tail while I fish for you. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.