Fragging corals is a big part of the hobby. Being able to acquire frags from others has benefits. Corals are shared rather than the constant harvesting of wild colonies in the ocean, and they are already accustomed to dwelling in a closed ecosystem. The giver prunes the colonies in their reef, allowing for better flow. They are able to 'bank' a coral with you in case theirs perishes for whatever reason. The receiver enjoys watching the little piece grow into something beautiful over time, and then will one day be a giver as well.
Working with acrylic isn't very hard, but you do have to be meticulous. Straight cuts are important, and the smoother the edges you achieve, the better your joints will bond. Many people wonder how sumps are assembled and don't realize that the bonding agent literally welds the two pieces into one piece with a chemical reaction that melts and merges the material. You need a triple cut (ATB) blade with 80 or more teeth for a clean edge.