About comments in the puzzle section:
The first question is very interesting, it is definitely something I will take into consideration. The question will shift a bit to the question whether or not we want to add information in general to the puzzle section. We have big plans to add different kinds of study/training material, aimed at specific traits/skills (e.g. training your imagination, starting with a random position and 8 (x) moves of notation with the instruction: put the position on a the board that remains after the suggested x moves). The puzzle section is aimed just for training the tactical skill, not to share some historical context or interesting facts about the problem. Probably other prospective features will be better suited for those things. Now, your idea can be put into practice in the 'Study' section (lidraughts.org/study and e.g. lidraughts.org/study/0X2SC8Qa).
About choice of capture fot the enemy colour:
No, that is not something you can expect. I try to choose the best option, a line that suits best for the problem (original idea, difficulty, aesthetics, creativity etc.) Of course you need to find all solutions to be sure the move that you play is winning. At the moment, you already can use Scan after the puzzle in played. In other words: you can look at all variations with top computer analysis directly after the puzzle is played (right above the notation field). Furthermore, the earlier mentioned studies are more suitable for showing sidelines and commentation.
Finally, if I find a puzzle with multiple suitable continuations, I will randomly choose one and create extra puzzles to show the other sweet tactical principles.