Drag & Drop Items

I created 5 D&D items that are very similar to each other. They work, but are wonky. I do not know whether it is bugs or (more likely) user errors. As I write this note, I will indicate the problems I could not get around. Your suggestions are graciously welcome:

1. From https://www.hebrewlion.com/learn, I click a child's face and am taken to a page that is dedicated only to the drag & drop. Let's use https://www.hebrewlion.com/learn/vocab/jeff/. The pw, if it prompts you, is simplyhebrew. Yes, I know I'm fast and loose with the passwords. It's cool.
2. SIZE: The first issue is that both the picture (400x400px) and the labels are well-proportioned to each other, but are huge in comparison with my screen. I have to adjust from my standard 130% to 50%--that's quite a bit!
   - I played with various picture sizes and went with this one deliberately. It was some time ago and do not recall my reasons.
   - If I reduce to 150x150 px, for instance, I imagine that hot spot placement would be really tough--or would it be the same, so long as I zoom appropriately?
   - What about the labels, if I reduce them drastically, can I control them still, or is there a size that's not worth going under? 
   - Font size: Below this line is a screen shot that shows I am using default font size. Is detault 100%? If so, the smallest size I see listed is 50%, which would not be enough. (Mathematically, if pic goes from 400px to 150px, then I would retain proportions by reducing font to 30% of its original size.
   
3. OK. So I zoomed out and am ready to do the puzzle (labeling face parts correctly). Here's how I want to set it up:
   - Drag as many times as you want, and it sticks if you drop it in the right place. This feature is working correctly.
   - OK. I dragged, everything stuck. At this point, I would like to be rewarded by a success message (preferably a randomly chosen success message from a group of 5 or 8). From what I saw, it is not possible. Is this true?
4. Since I couldn't get a success message upon completion, I decided to add the Check button at bottom.
   - Upon finishing the puzzle, I click Check.
   - My previously blue labels all turn red, each of them displays a red x at the bottom right (implying wrong, I don't want this). The Check button is replaced by a green line, then a star, then 1/1. This implies that I got 1 out of 1 items correct--but there are actually 12 labels altogether. It should say 12/12. Finally, there's a Retry button. Look, for this puzzle, the Check button should go away altogether,  The reason I have it visible is that it enables the Retry button that allows the user to do the puzzle  over.